Impact of Rosuvastatin Treatment on HDL-Induced PKC-βII and eNOS Phosphorylation in Endothelial Cells and Its Relation to Flow-Mediated Dilatation in Patients with Chronic Heart Failure

Protein kinase C: A potential therapeutic target for endothelial dysfunction in diabetes

Protein kinase C (PKC) is a family of serine/threonine protein kinases that play an important role in many organs and systems and whose activation contributes significantly to endothelial dysfunction in diabetes. The increase in diacylglycerol (DAG) under high glucose conditions mediates PKC activation and synthesis, which stimulates oxidative stress and inflammation, resulting in impaired endothelial cell function. This article reviews the contribution of PKC to the development of diabetes-related endothelial dysfunction and summarizes the drugs that inhibit PKC activation, with the aim of exploring therapeutic modalities that may alleviate endothelial dysfunction in diabetic patients.

Molecular Mechanisms and Therapeutic Implications of Endothelial Dysfunction in Patients with Heart Failure

Heart failure is a complex medical syndrome that is attributed to a number of risk factors; nevertheless, its clinical presentation is quite similar among the different etiologies. Heart failure displays a rapidly increasing prevalence due to the aging of the population and the success of medical treatment and devices. The pathophysiology of heart failure comprises several mechanisms, such as activation of neurohormonal systems, oxidative stress, dysfunctional calcium handling, impaired energy utilization, mitochondrial dysfunction, and inflammation, which are also implicated in the development of endothelial dysfunction. Heart failure with reduced ejection fraction is usually the result of myocardial loss, which progressively ends in myocardial remodeling. On the other hand, heart failure with preserved ejection fraction is common in patients with comorbidities such as diabetes mellitus, obesity, and hypertension, which trigger the creation of a micro-environment of chronic, ongoing inflammation. Interestingly, endothelial dysfunction of both peripheral vessels and coronary epicardial vessels and microcirculation is a common characteristic of both categories of heart failure and has been associated with worse cardiovascular outcomes. Indeed, exercise training and several heart failure drug categories display favorable effects against endothelial dysfunction apart from their established direct myocardial benefit.

Statin-Induced Nitric Oxide Signaling: Mechanisms and Therapeutic Implications

In addition to their cholesterol-lowering effects, statins are associated with pleiotropic effects including improvements in heart failure (HF), reduced blood pressure, prevention of the rupture of atherosclerotic plaques and improved angiogenesis. In addition to these cardiovascular benefits, statins have been implicated in the treatment of neurological injuries, cancer, sepsis, and cirrhosis. These cholesterol-independent beneficial effects of statins are predominantly mediated through signaling pathways leading to increased production and bioavailability of nitric oxide (NO). In this review, the mechanistic pathways and therapeutic effects of statin-mediated elevations of NO are described and discussed.

Matrine attenuates high-fat diet-induced in vivo and ox-LDL-induced in vitro vascular injury by regulating the PKCα/eNOS and PI3K/Akt/eNOS pathways

Lipid metabolism disorders lead to vascular endothelial injury. Matrine is an alkaloid that has been used to improve obesity and diabetes and for the treatment of hepatitis B. However, its effect on lipid metabolism disorders and vascular injury is unclear. Here, we investigated the effect of matrine on high‐fat diet fed mice and oxidized low‐density lipoprotein (ox‐LDL)‐induced human umbilical vein endothelial cells (HUVECs). Computational virtual docking analyses, phosphoinositide 3‐kinase (PI3K) and protein kinase C‐α (PKCα) inhibitors were used to localize matrine in vascular injuries. The results showed that matrine‐treated mice were more resistant to abnormal lipid metabolism and inflammation than vehicle‐treated mice and exhibited significantly alleviated ox‐LDL‐stimulated dysfunction of HUVECs, restored diminished nitric oxide release, decreased reactive oxygen species generation and increased expression phosphorylation of AKT‐Ser473 and endothelial nitric oxide synthase (eNOS)‐Ser1177. Matrine not only up‐regulates eNOS‐Ser1177 but also down‐regulates eNOS‐Thr495, a PKCα‐controlled negative regulator of eNOS. Using computational virtual docking analyses and biochemical assays, matrine was also shown to influence eNOS/NO via PKCα inhibition. Moreover, the protective effects of matrine were significantly abolished by the simultaneous application of PKCα and the PI3K inhibitor. Matrine may thus be potentially employed as a novel therapeutic strategy against high‐fat diet‐induced vascular injury.

Effect of rosuvastatin on fasting and postprandial endothelial biomarker levels and microvascular reactivity in patients with type 2 diabetes and dyslipidemia: a preliminary report

Background

The cardiovascular benefits of statins have been proven, but their effect on circulation in small vessels has not been examined fully. We investigated the effect of 20 mg rosuvastatin on biomarkers, including paraoxonase-1 (PON-1) and asymmetric dimethylarginine (ADMA), and on microvascular reactivity.

Method

We enrolled 20 dyslipidemic patients with type 2 diabetes and 20 age- and body mass index (BMI)-matched healthy controls. Rosuvastatin (20 mg/day) was given to the patient group for 12 weeks. Biochemical parameters, including PON-1 and ADMA, were compared between the patient and control groups, and before and after rosuvastatin treatment in the patient group. Fasting and 2 h postprandial levels of PON-1 and ADMA after mixed-meal challenge were also compared. Microvascular reactivity in a peripheral artery was examined using laser Doppler flowmetry.

Results

The respective mean ± standard deviation of age and BMI were 50.1 ± 3.8 year and 25.8 ± 3.7 kg/m² in the patients and 50.2 ± 3.2 year and 25.4 ± 3.4 kg/m² in the controls. The patient group had worse profiles of cardiometabolic biomarkers, including PON-1 and ADMA, than the controls. In the patients treated with 20 mg rosuvastatin, low-density lipoprotein (LDL)-cholesterol decreased from 147.2 ± 26.5 to 68.3 ± 24.5 mg/dL and high-density lipoprotein (HDL)-cholesterol increased from 42.4 ± 5.2 to 44.7 ± 6.2 mg/dL (both P < 0.05). Both fasting and 2 h postprandial levels of PON-1 increased and those of ADMA decreased after treatment with rosuvastatin for 12 weeks. The changes in postprandial levels of both biomarkers were greater than those after fasting. Microcirculation assessed as reactive hyperemia in the patients after an ischemic challenge increased significantly from 335.3 ± 123.4 to 402.7 ± 133.4% after rosuvastatin treatment. The postprandial changes in the biomarkers were significantly associated with improvement of microvascular reactivity.

Conclusions

Rosuvastatin treatment for 12 weeks improved microvascular reactivity with concomitant beneficial changes in the postprandial levels of PON-1 and ADMA. These results suggest that rosuvastatin improves the postprandial cardiometabolic milieu in type 2 diabetes.

Trial registration ClinicalTrials.gov: NCT02185963 (July 7, 2014)

Electronic supplementary material

The online version of this article (10.1186/s12933-017-0629-0) contains supplementary material, which is available to authorized users.