Effects of the Cdc2-like kinase-family and DNA topoisomerase I on the alternative splicing of eNOS in TNF-alpha-stimulated human endothelial cells.
Nitric oxide (NO) is synthesized by endothelial nitric oxide synthase (eNOS) and plays an important role in vascular homeostasis and cardiovascular diseases. It has recently been shown that increased expression of alternatively spliced eNOS isoforms eNOS 13A, B and C and heterodimerization with 'full-length' eNOS is associated with a decreased eNOS activity. The regulatory pathways enabling this phenomenon are completely unknown. This study examined the effect of Cdc2-like kinases and DNA topoisomerase I on eNOS splicing in TNF-alpha-induced human umbilical vein endothelial cells (HUVECs). We found that inhibition of DNA topoisomerase I, but not Cdc2-like kinases, prevents the TNF-alpha-induced increase in eNOS isoform expression and NO reduction in HUVEC. Moreover, we show that the inhibition of DNA topoisomerase I or the Cdc2-like kinases differently modulates the phosphorylation of the serine/arginine-rich proteins SRp75 and SRp55. Our results demonstrate, for the first time, that DNA topoisomerase I but not Cdc2-like kinases serves as an important regulator of the differential eNOS isoform expression in endothelial cells, thereby modulating the TNF-alpha-induced eNOS activity switch.
Eisenreich
Andreas
A
Charité - Universitätsmedizin Berlin, Campus Benjamin Franklin, Centrum für Herz- und Kreislaufmedizin, D-12200 Berlin, Germany.
Boltzen
Ulrike
U
Poller
Wolfgang
W
Schultheiss
Heinz-Peter
HP
Rauch
Ursula
U
D017398:Alternative Splicing / Q000187:drug effects; D016203:CDC2 Protein Kinase / Q000378:metabolism* / Q000494:pharmacology; D004264:DNA Topoisomerases, Type I / Q000378:metabolism* / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000201:enzymology*; D006801:Humans; D009569:Nitric Oxide / Q000032:analysis; D052250:Nitric Oxide Synthase Type III / Q000235:genetics*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D014471:Umbilical Veins / Q000187:drug effects / Q000201:enzymology
D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; D016203:CDC2 Protein Kinase; D004264:DNA Topoisomerases, Type I