The L-Arginine: Nitric Oxide Pathway Contributes to the Acute Release of Tissue Plasminogen Activator in vivo in Man

The induced differentiation of F9 cells by retinoic acid (RA) and cyclic AMP (cAMP) activated transcription of the tissue plasminogen activator (t-PA) gene. This differentiation-responsive regulation of the t-PA promoter was also observed in transient assays. Multiple sequence elements within 243 bp of t-PA DNA contributed to the high level of transcription in retinoic acid- and cyclic AMP-differentiated cells. To investigate the factors involved in controlling t-PA transcription upon differentiation, we used F9 cell extracts to examine proteins that bind two proximal promoter elements. These elements (boxes 4 and 5) are homologous to GC boxes that are known binding sites for transcription factor Sp1. Mobility shift assays in the presence and absence of anti-Sp1 antibodies demonstrated that the proteins which bound to this region were immunologically related to human Sp1. The proteins also had a DNA-binding specificity similar to that of a truncated form of Sp1. Mutations of the GC motif within boxes 4 and 5 that interfered with Sp1 binding reduced in parallel the binding of the F9 cellular factors and lowered transcription in vitro as well as in vivo. Although this proximal region of the t-PA promoter was active in vivo only in differentiated cells, the Sp1-like binding proteins were present in equal concentrations and had similar properties in extracts of both stem and differentiated cells. These data suggest that other cellular elements participate with this Sp1-like factor in controlling differentiation-specific expression.

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In vivo ultrasound-activated delivery of recombinant tissue plasminogen activator from the cavity of sub-micrometric capsules

Journal of Controlled Release ◽

10.1016/j.jconrel.2019.07.017 ◽

2019 ◽

Vol 308 ◽

pp. 162-171 ◽

Cited By ~ 4

Author(s):

Clara Correa-Paz ◽

María F. Navarro Poupard ◽

Ester Polo ◽

Manuel Rodríguez-Pérez ◽

Pablo Taboada ◽

...

Keyword(s):

Plasminogen Activator ◽

Tissue Plasminogen Activator ◽

Recombinant Tissue Plasminogen Activator ◽

Tissue Plasminogen

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Tissue Plasminogen Activator Expression in Endothelial Cells Exposed to Cyclic Strain in Vitro

Cell Transplantation ◽

10.1177/096368979200100108 ◽

1992 ◽

Vol 1 (1) ◽

pp. 43-50 ◽

Cited By ~ 46

Author(s):

Toshiaki Iba ◽

Bauer E. Sumpio

Keyword(s):

Endothelial Cells ◽

Plasminogen Activator ◽

Tissue Plasminogen Activator ◽

Cyclic Strain ◽

Neutral Position ◽

Messenger Ribonucleic Acid ◽

Tissue Plasminogen ◽

Pai 1

The effects of cyclic strain on the production of tissue plasminogen activator (tPA) and type 1 plasminogen activator inhibitor (PAI-1) by cultured endothelial cells (EC) were examined. Human saphenous vein EC were seeded in selective areas of culture plates with flexible membrane bottoms (corresponding to specific strain regions) and grown to confluence. Membranes were deformed by vacuum (-20 kPa) at 60 cycles/min (0.5 s strain alternating with 0.5 s relaxation in the neutral position) for 5 days. EC grown in the periphery were subjected to 7-24% strain, while cells grown in the center experienced less than 7% strain. The results show a significant increase in immunoreactive tPA production on days 1, 3 and 5 compared to day 0 in EC subjected to more than 7% cyclic strain. There was no significant elevation of tPA in the medium of EC subjected to less than 7% strain. tPA activity could only be detected in the medium of EC subjected to more than 7% cyclic strain. PAI-1 levels in the medium were not significantly different in either group. In addition, immunocytochemical detection of intracellular tPA and messenger ribonucleic acid (mRNA) expression of tPA (assessed by the reverse transcriptase polymerase chain reaction utilizing tPA specific sense and antisense primers) was significantly increased in EC subjected to more than 7% cyclic strain. We conclude that a 60 cycles/min regimen of strain that is greater than 7% can selectively stimulate tPA production by EC in vitro and may contribute to the relative nonthrombogenicity of the endothelium in vivo.

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