Regulation of endothelin synthesis by extracellular matrix in human endothelial cells.
BACKGROUND
Vascular diseases are characterized by the presence of structural changes and the progressive loss of endothelial function. Although the biochemical basis of these structural changes have started to be outlined, it seems that accumulation of normal extracellular matrix proteins as well as the appearance of interstitial collagens, mainly collagen type I, characterize this process. On the other hand, a role for endothelial vasoactive factors has been proposed in the genesis of endothelial dysfunction, and it is generally accepted that changes in extracellular matrix composition may modify cell behavior.


METHODS
Experiments were designed to test the influence of the supporting matrix on endothelin-1 (ET-1) synthesis by endothelial cells. Northern blot experiments were performed to analyze the prepro-endothelin-1 (prepro-ET-1) mRNA expression. ET-1 production was measured by ELISA.


RESULTS
Cells grown on collagen type I (Col I) showed an increase of prepro-ET-1 mRNA level when compared with cells cultured on collagen type IV (Col IV). According to these results, the release of ET-1 to culture medium was also higher in Col I-grown cells than in those cultured on Col IV. Treatment of cells with a peptide that interferes with Col I integrins (D6Y), or with protein tyrosine kinase inhibitors such as genistein and herbimycin, completely abolished the effect of Col I. Moreover, experiments with antibodies against integrins suggest that these cell surface receptors could be involved in the modulation of ET-1 system by extracellular matrix.


CONCLUSIONS
These results suggest that the presence of an abnormal extracellular matrix could stimulate endothelin synthesis by human endothelial cells, through integrin activation.
Department of Physiology, Alcalá University, Madrid, Spain.
Laura
L
González-Santiago
Susana
S
López-Ongil
Mercedes
M
Griera
Manuel
M
Rodríguez-Puyol
Diego
D
Rodríguez-Puyol
D002478:Cells, Cultured; D024042:Collagen Type I / Q000494:pharmacology; D024141:Collagen Type IV / Q000494:pharmacology; D019332:Endothelin-1 / Q000235:genetics*; D016232:Endothelins / Q000235:genetics; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology*; D005109:Extracellular Matrix / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D011498:Protein Precursors / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D014471:Umbilical Veins / Q000166:cytology
D024042:Collagen Type I; D024141:Collagen Type IV; D019332:Endothelin-1; D016232:Endothelins; D011498:Protein Precursors; D012333:RNA, Messenger