Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
Board

Endothelial cells (EC) appear to sense mechanical forces partly via structures located at their abluminal surface which may involve signalling via cell-matrix connections. We therefore studied the influence of different matrix proteins on shear stress induced eNOS expression. Primary porcine aortic EC were seeded onto non coated glass plates (NC-EC) or on those precoated with fibronectin (FN-EC), laminin I (LN-EC) or collagen (CL-EC). A 6 hours' shear stress of 16dyn/cm² was applied. After reaching confluency, only LN-EC showed detectable amounts of laminin I in their underlying matrix and responded with a significant, 2-fold increase of eNOS mRNA to shear stress. Likewise, increased eNOS protein and enhanced NO synthesis were found in these cells. Preincubation with YIGSR, a peptide that inhibits EC binding to laminin by a 67 KDa binding protein (LBP) abolished the increase of eNOS expression, whereas a control peptide did not. In contrast, FN-EC and NC-EC did not respond while CL-EC showed only a weak response. It is concluded that a laminin-cell interaction via the 67 kDa LBP is pivotal in the induction of eNOS expression by shear stress. The results further suggest that the matrix composition may decisively modulate shear stress effects on vascular gene expression.

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Presentation Number SApohl0397
Keywords: laminin, laminin receptor, nitric oxide, NO synthase