Association between P-selectin levels and left atrial blood stasis in patients with nonvalvular atrial fibrillation

BACKGROUND

P-selectin - a biomarker of platelet and endothelial cell activation is elevated in patients with non-valvular atrial fibrillation (NVAF). However, the association between sP-selectin level and thromboembolic complications in NVAF patients remains controversial. We tested the hypothesis that plasma soluble P-selectin (sPSL) level correlates with the measures of left atrial blood stasis in NVAF.

METHODS

Plasma sPSL concentration was measured using solid-phase ELISA in 103 NVAF patients (age 63 ± 14 years; 26% women) and 48 normal sinus rhythm controls (NSR; age 64 ± 14 years; 41% women) who were not on aspirin. Within the group of NVAF cases, 27 had no spontaneous echocardiographic contrast (SEC) detected by transesophageal echocardiography, 31had mild SEC, 15 moderate, 20 severe, and 10 patients had left atrial appendage thrombus (LAAT).

RESULTS

The median soluble sPSL level was higher in NVAF cases compared to NSR controls [(interquartile range) 26 (20-32) ng/mL vs 22 (15-29) ng/mL, p = 0.0045]. Only NVAF patients with CHA₂DS₂-VASc score ≥ 1 had higher sPSL level compared to NSR controls. Patients with severe SEC had significantly higher sPSL levels [32 (24-38) ng/mL] compared to all other NVAF patients (p = 0.0042) and to NSR controls (p < 0.0001). Also NVAF patients with LAAT had higher sPSL level compared to NSR controls.

CONCLUSIONS

There is a direct correlation between p-selectin level and severe blood stasis in the left atrium. Only NVAF patients with CHA₂DS₂-VASc score ≥ 1 or with LAAT had higher sPSL level compared to NSR controls.

Fibrillin-1 regulates mesangial cell attachment, spreading, migration and proliferation

The microfibrillar protein fibrillin-1 is present in many organs, including the vasculature, eye, and dermis, and is thought to convey structural anchorage and elastic strength. Fibrillin-1 is also a component of the mesangial matrix. To assess the functional relevance of fibrillin-1 for cell-matrix interactions in the glomerulus, we studied the attachment, spreading, migration and proliferation of mesangial cells on fibrillin-1 and the regulation of fibrillin-1 in experimental anti-Thy1.1 nephritis displaying mesangial cell migration and proliferation in vivo. During the acute phase of experimental Thy1.1 nephritis, glomerular fibrillin-1 messenger ribonucleic acid expression and protein immunoreactivity were significantly induced as compared to controls. In a hexosaminidase-based adhesion assay, mesangial cells showed concentration-dependent attachment to fibrillin-1, similar to what was observed for fibronectin. The cell attachment was Arg-Gly-Asp dependent. Further, fibrillin-1 significantly promoted spreading and focal contact formation detected by immunostaining for vinculin. Mesangial cell migration, assessed by a transmigration assay, and proliferation, measured by a 5-bromo-2'-deoxy-uridine incorporation assay, were augmented by fibrillin-1. In diabetic mice underexpressing fibrillin-1, glomerular cell proliferation, determined by counting proliferating cell nuclear antigen-positive cells in renal sections, was significantly lower than in diabetic control mice. We conclude that fibrillin-1 promotes mesangial cell attachment, spreading, migration, and proliferation. We speculate that fibrillin-1 may thus contribute to mesangial hypercellularity during glomerular disease.

Expression of latent matrix metalloproteinase 9 (MMP-9) predicts survival in advanced ovarian cancer

OBJECTIVE

Matrix metalloproteinases (MMPs) are frequently expressed in malignant tumors and play an important role in tumor invasion and metastasis. MMP-2 and MMP-9 expression has been correlated with poor survival in some tumors, but data for ovarian cancer are lacking, despite clinical trials with MMP inhibitors. The aim of this study was to assess activity of MMP-2 and MMP-9 and correlate it to prognosis in ovarian cancer.

METHODS

MMP-2 and MMP-9 gelatinolytic activity was analyzed in 84 patients with advanced ovarian cancer FIGO stage III and 19 benign ovarian tumors by gelatin zymography. MMP-9 immunoreactivity was detected by immunohistochemistry and gelatinolytic activity was localized in ovarian cancer tissue by in situ zymography.

RESULTS

were correlated with patient survival, with a median follow-up period of 55 months. Results. Median pro-MMP-9 activity was at 0.00 U/microg protein in benign ovarian tissues and 4.82 U/microg protein in ovarian cancer (P = 0.001); activated MMP-9 was not detected. Pro-MMP-2 expression in benign ovarian tissue did not differ from that of malignant ovarian tissue, whereas active MMP-2 was present in 52% of ovarian cancers, but absent in benign ovarian tissues. Analyzing all patients high pro-MMP-9 activity was associated with short overall survival (P = 0.019) while pro-MMP-2 and activated MMP-2 did not predict overall survival. When analyzing the subgroups of patients with and without residual tumor mass at the time of surgery, pro-MMP-9 was of prognostic value only in the subgroup of patients with no residual tumor mass. In univariate analysis pro-MMP-9 activity, residual tumor mass, age, ascites volume, and grading were of prognostic significance for overall survival. However, in multivariate analyses, including all biological and clinicopathologic variables, only pro-MMP-9 and residual disease remained statistically independent prognostic factors. In situ zymography localized gelatinolytic activity predominantly to the tumor cell nests displaying MMP-9 immunoreactivity.

CONCLUSIONS

Pro-MMP-9 gelatinolytic activity, but not active MMP-2 or MMP-9, serves as a useful statistically independent prognostic factor in ovarian cancer FIGO stage III, thus helping to identify ovarian cancer patients with an aggressive form of the disease.

Increased expression of matrix metalloproteinases (MMP)-2, MMP-9, and the urokinase-type plasminogen activator is associated with progression from benign to advanced ovarian cancer

Proteases are linked to the malignant phenotype of different solid tumors. Therefore, the expression of the matrix metalloproteinase (MMP)-2 and MMP-9 and of the serine protease urokinase-type plasminogen activator (uPA) and its inhibitor plasminogen activator inhibitor type 1 (PAI-1) in the progression of ovarian cancer was investigated. Gelatinolytic activity and protein expression of MMP-2 and MMP-9 were analyzed in tissue extracts of 19 cystadenomas and 18 low malignant potential (LMP) tumors, as well as 41 primary tumors of advanced ovarian cancer stage International Federation of Gynecology and Obstetrics IIIc/IV and their corresponding omentum metastases by quantitative gelatin zymography and Western blot. In the same tissue extracts, antigen levels of uPA and its inhibitor PAI-1 were determined by ELISA. Protein expression of pro-MMP-2 (72 kDa) and pro-MMP-9 (92 kDa as well as antigen levels of uPA and PAI-1 were low in benign ovarian tumors but increased significantly from LMP tumors to advanced ovarian cancers. The highest values of all of the proteolytic factors were detected in omentum metastases. Active MMP-2 enzyme (62 kDa) was detected only in ovarian cancer (66%) and corresponding metastases (93%) but never in benign or LMP tumors. The activation rate of MMP-2 to its active isoform was higher in the metastases. Comparing both proteolytic systems, higher PAI-1 concentrations were consistently found in cancers with high pro-MMP-9 expression. These data indicate that members of the plasminogen activator system, as well as the metalloproteinases MMP-2/9, increase with growing malignant potential of ovarian tumors. These findings are of particular relevance to the development of protease inhibitors as new therapeutic approaches in ovarian cancer.