The role of urotensin II and atherosclerotic risk factors in patients with slow coronary flow

Relationship between increased systemic immune-inflammation index and coronary slow flow phenomenon

Background

Systemic immune-inflammation index (SII, platelet × neutrophil/lymphocyte ratio), a new marker of inflammation, is associated with adverse cardiovascular events, but its relationship with coronary slow flow phenomenon (CSFP) is unclear. Therefore, we aimed to investigate the relationship between SII and CSFP.

Methods

We enrolled consecutive patients who presented with chest pain, with normal/near-normal coronary angiography findings (n = 89 as CSFP group; n = 167 as control group). The baseline characteristics, laboratory parameters and angiographic characteristics of the two groups were compared.

Results

SII levels were significantly higher in the CSFP group than in the control group (409.7 ± 17.7 vs. 396.7 ± 12.7, p < 0.001). A significant positive correlation between SII and the mean thrombolysis in myocardial infarction frame count (mTFC) was found (r = 0.624, p < 0.001). SII increased with the number of coronary arteries involved in CSFP. In multivariate logistic regression analysis, SII/10 was an independent predictor of CSFP (odds ratio: 1.739, p < 0.001). In addition, the SII level > 404.29 was a predictor of CSFP with 67.4% sensitivity and 71.9% specificity.

Conclusions

SII can predict the occurrence of CSFP.

Salidroside and isorhamnetin attenuate urotensin II-induced inflammatory response in vivo and in vitro: Involvement in regulating the RhoA/ROCK II pathway

Urotensin II (UII), a vital vasoconstrictor peptide, causes an inflammatory response in the pathogenesis of atherosclerosis. Previous studies have reported that the Ras homolog gene family, member A (RhoA)/Rho kinases (ROCK) pathway modulates the inflammatory response of the atherosclerotic process. However, to the best of our knowledge, whether the RhoA/ROCK pathway mediates the inflammatory effect of UII has not been previously elucidated. Salidroside and isorhamnetin are two early developed antioxidant Tibetan drugs, both displaying cardioprotective effects against atherosclerosis. Therefore, the aim of the present study was to investigate the protective effects of salidroside, isorhamnetin or combination of these two drugs on the UII-induced inflammatory response in vivo (rats) or in vitro [primary vascular smooth muscle cells (VSMCs)], as well as to examine the role of the RhoA/ROCK pathway in these processes. The levels of inflammatory markers were measured via ELISA. The mRNA and protein expression levels of RhoA and ROCK II were detected using reverse transcription-quantitative PCR assay and western blot analysis. It was demonstrated that salidroside, isorhamnetin and both in combination decreased the levels of the serum pro-inflammatory cytokines TNF-α and IL-1β, as well as increased the levels of the anti-inflammatory cytokine IL-10 and macrophage migration inhibitory factor in rats with subacute infusion of UII and in the culture supernatant from primary VSMCs-exposed to UII. Moreover, salidroside, isorhamnetin and both in combination attenuated the mRNA and protein expression levels of RhoA and ROCK II in vivo and in vitro, at concentrations corresponding to human therapeutic blood plasma concentrations. Thus, these drugs could inhibit the RhoA/ROCK II pathway under UII conditions. The combination of salidroside and isorhamnetin did not display a stronger inhibitory effect on the inflammatory response and the RhoA/ROCK II pathway compared with salidroside and isorhamnetin in isolation. Collectively, the results indicated that salidroside, isorhamnetin and both in combination inhibited the RhoA/ROCK II pathway, which then attenuated the inflammatory response under UII-induced conditions, resulting in cardioprotection in atherosclerosis.

The Protective Effect of Total Flavones from Rhododendron simsii Planch. on Myocardial Ischemia/Reperfusion Injury and Its Underlying Mechanism

Objectives

Total flavones from Rhododendron simsii Planch. (TFR) are the effective part extracted from the flowers of Rhododendron simsii Planch. and have obvious protective effects against cerebral ischemic or myocardial injuries in rabbits and rats. However, their mechanism of cardioprotection is still unrevealed. Therefore, the present study was designed to investigate the effect of TFR on myocardial I/R injury and the underlying mechanism.

Methods

TFR groups were treated by gavage once a day for 3 days at a dose of 20, 40, and 80 mg/kg, respectively, and then the model of myocardial I/R injury was established. Myocardial infarction, ST-segment elevation, and the expression of UTR, ROCK1, ROCK2, and p-MLC protein in rat myocardium were determined at 90 min after reperfusion. UTR siRNA in vivo transfection and competition binding assay method were used to study the relationship between the protective effect of TFR and UTR.

Results

The expression of UTR protein markedly decreased in myocardium of UTR siRNA transfection group rats. TFR could significantly reduce the infarct size and inhibit the increase of RhoA activity and ROCK1, ROCK2, and p-MLC protein expressions both in WT and UTR knockdown rats. The reducing rate of TFR in myocardial infarction area, RhoA activity, and ROCK1, ROCK2, and p-MLC protein expressions in UTR knockdown rats decreased markedly compared with that in WT rats. In addition, TFR had no obvious effect on the increase of ΣST in UTR knockdown rats in comparison with that in model group. In particular, TFR could significantly inhibit the combination of [¹²⁵I]-hu-II and UTR, and IC₅₀ was 0.854 mg/l.

Conclusions

The results indicate that the protective effect of TFR on I/R injury may be correlated with its blocking UTR and the subsequent inhibition of RhoA/ROCK signaling pathway.