The role of HMG-CoA reductase inhibition in endothelial dysfunction and inflammation

Statin-induced inhibition of HMG-CoA reductase reduces cholesterol production and prevents the formation of many non-steroidal isoprenoid compounds, such as farnesylpyrophosphate and geranylgeranylpyrophosphate, that act as lipid attachments for the post-translational modification of various proteins, including the G-proteins and transcription factors involved in a number of cell processes. However, the blockade of isoprenylation elicited by statin treatment also has biological effects on cell function that go beyond the decrease in cholesterol synthesis: these are the so-called “pleiotropic” effects that mainly relate to vascular function. Endothelial dysfunction is an independent predictor of cardiovascular events that correlates with inflammation markers/mediators and robust predictors of cardiovascular diseases such as increased high-sensitivity C-reactive protein levels. The results of in vivo and in vitro studies indicate that the statins have beneficial effects unrelated to cholesterol lowering, such as improving endothelial function, increasing myocardial perfusion, and enhancing the availability of nitric oxide. This review describes the pleiotropic effects of statins that may be involved in modulating/preventing endothelial dysfunction and inflammatory processes, as well as the cellular and molecular mechanisms through which they improve endothelial function

Terutroban, a Thromboxane/Prostaglandin Endoperoxide Receptor Antagonist, Increases Survival in Stroke-Prone Rats by Preventing Systemic Inflammation and Endothelial Dysfunction: Comparison with Aspirin and Rosuvastatin

ABSTRACT This study investigated the efficacy of terutroban, a specific thromboxane/prostaglandin endoperoxide receptor antagonist, on stroke incidence in spontaneously hypertensive strokeprone rats (SHRSP). The effects of terutroban were compared with those of aspirin, another antiplatelet agent, and rosuvastatin, known to exert end-organ protection in SHRSP. Saltloaded male SHRSP were treated orally once a day with vehicle, terutroban (30 mg/kg/day), aspirin (60 mg/kg/day), or rosuvastatin (10 mg/kg/day). Compared with vehicle, and regardless of any effect on blood pressure or serum thromboxane B 2 levels, terutroban significantly increased survival (p Ͻ 0.001) as a consequence of a delayed brain lesion occurrence monitored by magnetic resonance imaging (p Ͻ 0.001), and a delayed increase of proteinuria (p Ͻ 0.001). Terutroban decreased cerebral mRNA transcription of interleukin-1␤, transforming growth factor-␤, and monocyte chemoattractant protein-1 after 6 weeks of dietary treatment. Terutroban also prevented the accumulation of urinary acute-phase proteins at high molecular weight, identified as markers of systemic inflammation, and assessed longitudinally by one-dimensional electrophoresis. Terutroban also has protective effects on the vasculature as suggested by the preservation of endothelial function and endothelial nitric-oxide synthase expression in isolated carotid arteries. These effects are similar to those obtained with rosuvastatin, and superior to those of aspirin. Terutroban increases survival in SHRSP by reducing systemic inflammation as well as preserving endothelial function. These data support clinical development of terutroban in the prevention of cerebrovascular and cardiovascular complications of atherothrombosis. Several clinical and experimental studies Spontaneously hypertensive stroke-prone rats (SHRSP) develop hypertension and proteinuria and die after the onset Article, publication date, and citation information can be found a

Statins inhibit the activation of Rho signaling, which negatively influences eNOS mRNA stability and activity, leading to an increased NO bioavailability

<p><b>Copyright information:</b></p><p>Taken from "The role of HMG-CoA reductase inhibition in endothelial dysfunction and inflammation"</p><p></p><p> 2007;3(5):567-577.</p><p>Published online Jan 2007</p><p>PMCID:PMC2291301.</p><p></p

Ang II and NO functions interplay to influence vascular tone, through different effects on RhoA pathway

<p><b>Copyright information:</b></p><p>Taken from "The role of HMG-CoA reductase inhibition in endothelial dysfunction and inflammation"</p><p></p><p> 2007;3(5):567-577.</p><p>Published online Jan 2007</p><p>PMCID:PMC2291301.</p><p></p

Microglia is a key player in the reduction of stroke damage promoted by the new antithrombotic agent ticagrelor

The ADP-responsive P2Y12 receptor is expressed on both platelets and microglia. Clinical data show that ticagrelor, a direct-acting, reversibly binding P2Y12-receptor antagonist, reduces total cardiovascular events, including stroke. In our present study, we investigated the expression of P2Y12 receptors and the effects of ticagrelor on brain injury in Sprague-Dawley rats subjected to a permanent middle cerebral artery occlusion (MCAo). Rats were treated per os with ticagrelor 3 mg/kg or vehicle at 10 minutes, 22, and 36 hours after MCAo and killed after 48 hours. Immunofluorescence analysis showed an ischemia-related modulation of the P2Y12 receptor, which is constitutively expressed in Iba1+ resting microglia. After MCAo, activated microglia was mainly concentrated around the lesion, with fewer cells present inside the ischemic core. Ticagrelor significantly attenuated the evolution of ischemic damage-evaluated by magnetic resonance imaging (MRI) at 2, 24, and 48 hours after MCAo-, the number of infiltrating cells expressing the microglia/monocyte marker ED-1, the cerebral expression of proinflammatory mediators (interleukin 1 (IL-1), monocyte chemoattractant protein 1 (MCP-1), nitric oxide synthase (iNOS)) and the associated neurologic impairment. In transgenic fluorescent reporter CX3CR1-green fluorescent protein (GFP) mice, 72 hours after MCAo, ticagrelor markedly reduced GFP + microglia and both early and late infiltrating blood-borne cells. Finally, in primary cultured microglia, ticagrelor fully inhibited ADP-induced chemotaxis (P<0.01). Our results show that ticagrelor is protective against ischemia-induced cerebral injury and this effect is mediated, at least partly, by inhibition of P2Y12-mediated microglia activation and chemotaxis