Distinct vascular effects of celecoxib and rofecoxib in vivo

Randomized controlled trials of cyclooxygenase (COX)‐2 selective NSAIDs, such as celecoxib and rofecoxib, revealed that these drugs confer a cardiovascular hazard, resulting mainly from suppression of COX‐2 derived prostacyclin (PGI 2 ). However, in contrast to increasing the risk of myocardial infarction and stroke, celecoxib reduces the incidence of vascular re‐occlusion after coronary angioplasty. Disruption of rodent COX‐2–derived PGI 2 in vascular cells and cardiomyocytes has recapitulated all elements of the cardiovascular hazard attributable to NSAIDs in humans. To investigate further the impact of COX‐2 inhibition in the vasculature, we examined the effects of therapeutic concentrations of celecoxib and rofecoxib on thrombosis and vascular injury. Furthermore, we used RNA sequencing (RNA‐Seq) to assess whether celecoxib and rofecoxib might elicit distinct genomic effects in mouse aorta. Measurement of thromboxane (TXM, an in vivo index of COX‐1 activity) and prostacyclin (PGIM, an in vivo index of COX‐2 activity) urinary metabolites showed that chronic oral administration of celecoxib (100mg/Kg/day) and rofecoxib (50mg/Kg/day) for three weeks caused a 50% inhibition of PGIM and had no effect on TXM as measured by mass spectrometry. Both celecoxib and rofecoxib augmented platelet deposition and prolonged platelet disaggregation after laser‐induced injury in the cremaster arterioles. No differences were observed between the two drug treatments. A similar effect was observed in mice lacking PGI 2 receptor IP. There was no additional pro‐thrombotic effect of these drugs on an IPKO background, consistent with suppression of COX‐2 dependent PGI 2 mediating the predisposition to thrombosis induced by celecoxib and rofecoxib. Celecoxib, but not rofecoxib, caused a reduction of neointimal hyperplasia and the intima/media ratio of injured femoral artery at 3 weeks after wire injury. To mimic consequences of the increased expression of interleukin (IL)‐1 after vascular injury, RNA‐seq analysis was carried out on total RNA from IL1‐beta stimulated aorta from mice fed with celecoxib, rofecoxib or regular chow for three weeks (n = 8 per group) and run on the Illumina HISEQ2000 platform. 447 transcripts were significantly differentially expressed (SDE) between celecoxib and control group and 5,074 transcripts were SDE between rofecoxib and control group (at a false discovery rate of 10%). Enrichment analysis performed with Enrichr (BMC Bionformatics. 2013;14:128) revealed “Focal adhesion” as the top cellular component enriched by the 200 transcripts SDE when celecoxib, but not rofecoxib were compared to the control group (p=1.2×10 −8 ). Focal adhesion plays essential roles in important biological processes activated during vascular injury including cell motility, cell proliferation and cell survival. Thus, both celecoxib and rofecoxib cause a similar predisposition to thrombosis in mice. Celecoxib, but not rofecoxib, reduces neointimal hyperplasia after vascular injury and COX‐2 independent genomic actions on focal adhesion might modulate this effect. The predisposition to thrombosis and attenuation of the response to vascular injury by therapeutic concentrations of celecoxib attained in mice recapitulates what has been found in humans. Support or Funding Information This study was supported by The Personalized NSAID Therapeutics Consortium (PENTACON: HL117798).