Thromb Haemost 2002; 88(01): 131-136
DOI: 10.1055/s-0037-1613165
Review Article
Schattauer GmbH

Identification of Potentially Effective Antisense Oligodeoxyribonucleotide (ODN) Sequences for Inhibiting Plasminogen Activator Inhibitor-2 (PAI-2) Production by Monocytes

Julia Humphries
1   Academic Dept of Surgery, GKT Medical School, Kings College, St Thomas´ Hospital, London
,
Kevin G. Burnand
1   Academic Dept of Surgery, GKT Medical School, Kings College, St Thomas´ Hospital, London
,
Philip Cunningham
2   Dept of Bioinformatics, Kings College, London
,
Adrian Brock
3   Dimbleby Cancer Research Unit, ICRF Laboratories, The Rayne Institute, Kings College, St Thomas´ Hospital, London
,
Nigel Westwood
4   Leukemia Science Laboratories, The Rayne Institute, Kings College, London
,
Alberto Smith
1   Academic Dept of Surgery, GKT Medical School, Kings College, St Thomas´ Hospital, London
› Author Affiliations
Further Information

Publication History

Received 28 September 2001

Accepted after resubmission 25 February 2002

Publication Date:
09 December 2017 (online)

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Summary

Objective

Monocyte fibrinolytic activity may influence thrombus resolution. The balance between uPA and PAI-2 could determine the fibrinolytic activity of the monocyte. Inhibiting PAI-2 production using specific antisense sequences might alter this balance. Selecting effective sequences is a problem as prediction of the secondary structure of target mRNA is difficult. This study reports the modification of a cell free system for rapid antisense screening.

Methods

Five 18-19 mer oligodeoxynucleotides (ODN), sequences A, B, K, T and Q, and their matched scrambled controls were designed and screened using a modified rabbit reticulocyte lysate transcription and translation system (RRL). Intracellular uptake of ODNs was confirmed by fluorescence microscopy, scanning laser confocal microscopy and fluorimetery. Monocytes were transfected with a liposome/ODN complex using sequences A, B, A + B combined, or T and PAI-2 levels measured by ELISA. Inhibition of PAI-2 production was calculated as a percentage of control levels (baseline and scrambled).

Results

(i) RRL System – Sequence A was the most effective inhibitor of PAI-2 production in this system (median 63%) compared with sequences, B median 9%, K median 14%, T median 11% and Q median –8% respectively (n = 3). Sequence A was the only sequence, which always inhibited PAI-2. This was confirmed using fluorescently labelled protein (n = 2). (ii) Monocyte transfection Fluorescence microscopy and fluorimetry showed that intracellular delivery of labelled antisense was only achieved when a liposome was used. Transfection of monocytes extracted from 5 subjects showed that sequence A significantly reduced PAI-2 production (mean % 41.4, sem 9.1) compared with sequences B (mean% 3.4, sem 8.9, p = 0.04), A + B (mean % 0.4, sem 7.8, p = 0.04), and T (mean % 5.4, sem 4.9, p = 0.01). Futher studies using sequence A on cells from 10 subjects showed a significant reduction in monocyte PAI-2 production (27.6 ng/ml, sem 3.9) compared with matched scrambled controls (mean 38.3 ng/ml, sem 4.5, p = 0.0112) and baseline (mean 51.4 ng/ml, sem 6.7, p = 0.0009).

Conclusion

Use of the RRL screening system allowed the selection of a novel antisense sequence, which significantly reduced PAI-2 production in monocytes.