Beyond lipid-lowering: effects of statins on endothelial nitric oxide

Cardiovascular Benefit of Statin Use Against Air Pollutant Exposure in Older Adults

BACKGROUND AND AIMS

Little is known about the cardiovascular benefit of statin use against ambient air pollution among older adults who are at higher risk of cardiovascular disease (CVD) potentially owing to age-related declines in cardiovascular functions along with other risk factors.

METHODS AND RESULTS

This retrospective, population-based cohort study consisted of adults aged 60 years and older free of CVD at baseline identified from the National Health Insurance Service (NHIS) database linked to the National Ambient Air Monitoring Information System (NAMIS) for average daily exposure to PM10 and PM2.5 in 2015 in the major metropolitan areas in the Republic of Korea. Follow-up period began on January 1, 2016 and lasted until December 31, 2021. Cox proportional hazards model was used to evaluate association of cardiovascular benefit with statin use against different levels of air pollutant exposure. Of 1,229,444 participants aged 60 years and older (mean age, 67.4; 37.7% male), 377,076 (30.7%) were identified as statin-users. During 11,963,322 person-years (PY) of follow-up, a total of 86,018 incident stroke events occurred (719.0 events per 100,000 PYs). Compared to statin non-user exposed to high level of PM10 (>50 µg/m3) and PM2.5 (>25 µg/m3), statin users had 20% (adjusted hazard ratio [HR], 0.80; 95% confidence intervals [CI], 0.75 to 0.85) and 17% (adjusted HR, 0.80; 95% CI, 0.80 to 0.86) lower adjusted risk of incident stroke for PM10 and PM2.5, respectively. Similar risk reduction for incident CVD was also found among statin-users exposed to low or moderate level of PM10 (≤50 µg/m3) and PM2.5 (≤25 µg/m3) exposure.

CONCLUSION

Among adults aged 60 years and older with high and low or moderate levels of exposure to PM10 and PM2.5, statin use was associated with a significantly lower risk of stroke.

The impact of pre-ictal statin use on vasospasm and outcome in aneurysmal subarachnoid hemorrhage

BACKGROUND

Pleiotropic effects of statins may be beneficial in alleviating cerebral vasospasm (VS) and improving outcome after aneurysmal subarachnoid hemorrhage (aSAH). Initiation of statin treatment at aSAH is not recommended; however, the effect of pre-ictal and continued statin use is not fully investigated.

METHODS

Retrospective study comparing aSAH patients admitted in 2012 to 2021 with pre-ictal statin use versus those not using statins. Patient entry variables, radiological/sonological VS, symptomatic VS, and radiologically documented delayed cerebral ischemia (DCI) were registered. Outcome was scored in terms of mortality, modified Rankin score, Glasgow outcome score extended, and levels of fatigue. Patients were compared on group level and in a case-control design.

RESULTS

We included 961 patients, with 204 (21.2%) statin users. Statin users were older and had more often hypertension. Severe radiological/sonological VS, symptomatic VS, and DCI were less frequent in statin users, and their length of stay was shorter. Mortality, functional outcome, and levels of fatigue were similar in both groups. When analyzing 89 pairs of statin users and non-statin users matched for age, aSAH severity, gender, and hypertension, we confirmed decreased radiological/sonological and symptomatic VS as well as shorter length of stay in statin users. They also had more often a favorable functional outcome and lower levels of fatigue.

CONCLUSIONS

Patients with pre-ictal and continued use of statins have a reduced occurrence of radiological/sonological and symptomatic VS, shorter length of stay, and more often favorable functional outcome, whereas mortality is similar to non-statin users. Even though larger multicenter studies with common, strict protocols for prevention, diagnosis, and treatment of vasospasm are needed to finally establish the value of statins in aSAH, continuation of pre-ictal statin use seems worthwhile.

Combined Therapy with Simvastatin- and Coenzyme-Q10-Loaded Nanoparticles Upregulates the Akt-eNOS Pathway in Experimental Metabolic Syndrome

In addition to their LDL-cholesterol-lowering effect, statins have pleiotropic beneficial effects on the cardiovascular system. However, long-term treatment with statins may be associated with serious side effects. With the aim to make statin therapy more effective, we studied the effects of simvastatin- and coenzyme-Q10-loaded polymeric nanoparticles on the lipid profile and nitric oxide (NO)/reactive oxygen species (ROS) balance in the heart and aorta of adult male obese Zucker rats. The rats were divided into an untreated group, a group treated with empty nanoparticles, and groups treated with simvastatin-, coenzyme Q10 (CoQ10)-, or a combination of simvastatin- and CoQ10-loaded nanoparticles (SIMV+CoQ10). After 6 weeks, the lipid profile in the plasma and the concentration of conjugated dienes in the liver were determined. Nitric oxide synthase (NOS) activity, Akt, endothelial NOS (eNOS), phosphorylated eNOS (p-eNOS), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and nuclear factor kappaB (NF-kappaB) protein expressions were measured in the heart and aorta. All simvastatin, CoQ10, and SIMV+CoQ10 treatments decreased plasma LDL levels, but only the combined SIMV+CoQ10 treatment increased NOS activity and the expression of Akt, eNOS, and p-eNOS in both the heart and the aorta. Interestingly, NADPH oxidase in the heart and NF-kappaB protein expression in the aorta were decreased by all treatments, including nanoparticles alone. In conclusion, only combined therapy with SIMV- and CoQ10-loaded nanoparticles increased NOS activity and upregulated the Akt-eNOS pathway in obese Zucker rats, which may represent a promising tool for the treatment of cardiometabolic diseases.

Bioadhesive Perivascular Microparticle-Gel Drug Delivery System for Intimal Hyperplasia Prevention: In Vitro Evaluation and Preliminary Biocompatibility Assessment

Intimal hyperplasia (IH) is an undesirable pathology occurring after peripheral or coronary bypass surgery. It involves the proliferation and migration of vascular smooth muscle cells, leading to a reduction in the diameter of the vascular lumen, which can lead to stenosis and graft failure. Topically applied atorvastatin (ATV) has been shown to slow down this process. To be effective, the drug delivery system should remain at the perivascular site for 5-8 weeks, corresponding to the progression of IH, and be capable of releasing an initial dose of the drug followed by a sustained release. Ideally, bioadhesion would anchor the gel to the application site. To meet these needs, we encapsulated ATV in a 2-component system: a hyaluronic acid-dopamine bioadhesive gel for rapid release and biodegradable microparticles for sustained release. The system was characterized by scanning electron microscopy, rheology, bioadhesion on porcine arteries, and a release profile. The rheological properties were adequate for perivascular application, and we demonstrated superior bioadhesion and cohesion compared to the control HA formulations. The release profile showed a burst, generated by free ATV, followed by sustained release over 8 weeks. A preliminary evaluation of subcutaneous biocompatibility in rats showed good tolerance of the gel. These results offer new perspectives on the perivascular application towards an effective solution for the prevention of IH.

Hyperuricemia induces endothelial dysfunction and accelerates atherosclerosis by disturbing the asymmetric dimethylarginine/dimethylarginine dimethylaminotransferase 2 pathway

Hyperuricemia is closely associated with the mobility and mortality of patients with cardiovascular diseases. However, how hyperuricemia accelerates atherosclerosis progression is not well understood. The balance between asymmetric dimethylarginine (ADMA) and dimethylarginine dimethylaminotransferases (DDAHs) is crucial to regulate vascular homeostasis. Therefore, we investigated the role of the ADMA/DDAH pathway in hyperuricemia-induced endothelial dysfunction and atherosclerosis and the underlying molecular mechanisms in endothelial cells (ECs) and apolipoprotein E-knockout (apoe-/-) mice. Our results demonstrated that uric acid at pathological concentrations increased the intracellular levels of ADMA and downregulated DDAH-2 expression without affecting DDAH-1 expression. Excess uric acid also reduced NO bioavailability and increased monocyte adhesion to ECs, which were abolished by using the antioxidant N-acetylcysteine, the nicotinamide adenine dinucleotide phosphate oxidase inhibitor apocynin, or DDAH-2 overexpression. In apoe-/- mice, treatment with oxonic acid, a uricase inhibitor, increased the circulating level of uric acid, cholesterol, and lipid peroxidation; exacerbated systemic and aortic inflammation; and worsened atherosclerosis compared with vehicle-treated apoe-/- mice. Furthermore, oxonic acid-treated apoe-/- mice exhibited elevated ADMA plasma level and downregulated aortic expression of DDAH-2 protein. Notably, DDAH-2 overexpression in the ECs of apoe-/- mice prevented hyperuricemia-induced deleterious effects from influencing ADMA production, lipid peroxidation, inflammation, and atherosclerosis. Collectively, our findings suggest that hyperuricemia disturbs the balance of the ADMA/DDAH-2 axis, results in EC dysfunction, and, consequently, accelerates atherosclerosis.

Possible mechanisms of cholesterol elevation aggravating COVID-19

Importance: Despite the availability of a vaccine against the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), humans will have to live with this virus and the after-effects of the coronavirus disease 2019 (COVID-19) infection for a long time. Cholesterol plays an important role in the infection and prognosis of SARS-CoV-2, and the study of its mechanism is of great significance not only for the treatment of COVID-19 but also for research on generic antiviral drugs. Observations: Cholesterol promotes the development of atherosclerosis by activating NLR family pyrin domain containing 3 (NLRP3), and the resulting inflammatory environment indirectly contributes to COVID-19 infection and subsequent deterioration. In in vitro studies, membrane cholesterol increased the number of viral entry sites on the host cell membrane and the number of angiotensin-converting enzyme 2 (ACE2) receptors in the membrane fusion site. Previous studies have shown that the fusion protein of the virus interacts with cholesterol, and the spike protein of SARS-CoV-2 also requires cholesterol to enter the host cells. Cholesterol in blood interacts with the spike protein to promote the entry of spike cells, wherein the scavenger receptor class B type 1 (SR-B1) plays an important role. Because of the cardiovascular protective effects of lipid-lowering therapy and the additional anti-inflammatory effects of lipid-lowering drugs, it is currently recommended to continue lipid-lowering therapy for patients with COVID-19, but the safety of extremely low LDL-C is questionable. Conclusions and Relevance: Cholesterol can indirectly increase the susceptibility of patients to SARS-CoV-2 and increase the risk of death from COVID-19, which are mediated by NLRP3 and atherosclerotic plaques, respectively. Cholesterol present in the host cell membrane, virus, and blood may also directly participate in the virus cell entry process, but the specific mechanism still needs further study. Patients with COVID-19 are recommended to continue lipid-lowering therapy.

The role of anti-proliferative effects of atorvastatin on uterine fibroids: findings from a clinical study

AIM

Uterine myomas/fibroids are one of the most common benign tumors of the reproductive system in women. Given pleiotropic effects of statins, the aim of this study is to evaluate the therapeutic effects of atorvastatin on uterine fibroids in women of reproductive age.

MATERIALS AND METHODS

This randomized clinical study included 90 women aged 35-45 years with uterine fibroids. The patients were randomly allocated into the intervention group (received one tablet, 20 mg of atorvastatin every day for three months) and placebo. Ultrasound was performed every month, and the change in the size of fibroids was recorded for each patient. At the end of the study, the data obtained were analyzed using SPSSv22 and a p value < .05 was considered statistically significant.

RESULTS

The mean age in the placebo and intervention group was 39.63 ± 36.3 and 40.35 ± 3.32 years, respectively. The number and location of the tumor was comparable for the two groups. We observed a statically significant reduction in fibroid size from the treatment initiation until completion of three months, (41.06 ± 6.68 mm³ vs 35.16 ± 6.67 mm³) p = .0001. However, the decrease in fibroid size from 1st month to the 3rd month was not statistically significant, p = .189 (36.71 ± 5.54 mm³ vs 35.16 ± 6.67 mm³).

CONCLUSION

This study shows that treatment with atorvastatin might positively reduce the size of fibroids. The decrease was only statistically significant during the first month. Further studies with a detailed analysis of the intervention's clinical impact are required to consider statins as a therapeutic tool.

Dual effects of atorvastatin on angiogenesis pathways in the differentiation of mesenchymal stem cells

Atorvastatin (ATO) can improve the transplantation efficacy of mesenchymal stem cells (MSCs) after acute myocardial infarction. The present study aimed at ATO effects on the angiogenesis-signaling pathways from MSCs' differentiation to tissue angiogenesis. MSCs were first prepared from BALB/c mouse bone marrow. MTT assay was then done for the biodegradability of MSCs with the extracellular matrix. After that, the differentiation of cells into the bone and fat tissues was confirmed by Alizarin and Oil Red O staining. The extracellular matrix was then combined with the cells to the implant. Animals were intraperitoneally treated with ATO (2 and 40 mg/kg, daily) three days before cell transplantation to one week after. Finally, the assays were carried out by electron microscopy, immunocytochemistry, ELISA, Western blot, and RT-qPCR techniques. A phase-contrast microscope confirmed the morphology of cells. The cell differentiation into bone and fat tissues was confirmed by Alizarin red staining and flow cytometry, and the cell proliferation was confirmed by MTT assay. Unlike ATO 40 mg/kg group, ATO 2 mg/kg was significantly increased the CD31, eNOS, podocalyxin, von Willibrand factor, and alpha-smooth muscle actin proteins levels compared to the control group in vitro experiment. The expression of CD31 and VEGF proteins, as angiogenesis markers, and Ki-67 protein, as a proliferation marker, was significantly higher in a low dose of ATO (2 mg/kg) than that of the control group in vivo experiment. Unlike ATO 40 mg/kg, the expression levels of ERK, AKT, NF-ҝB, Rho, STAT3, Ets-1, HIF-1α, and VEGF proteins and genes were significantly increased in ATO 2 mg/kg compared to the control. A low dose of ATO can be a beneficial tool in the function of MSCs and their differentiation to tissue angiogenesis.

The protective effect of statins against pressure ulcers in stroke patients: A propensity-score matched study based on a real-world database

BACKGROUND AND AIMS

Limited information is available regarding the association between statins and pressure ulcers. The purpose of this study is to evaluate the beneficial effects of statins on pressure ulcers in stroke patients.

METHODS

Using the claims data of Taiwan's National Health Insurance, we conducted a retrospective cohort study and identified new-onset stroke patients in 2000-2004. The propensity-score matching procedure was used to select eligible stroke patients with (n = 49,919) and without (n = 49,919) the use of statins. These two groups were followed until the end of 2009 to track the occurrence of pressure ulcers. Multivariate Cox proportional hazard models were conducted to calculate adjusted hazard rations (HRs) and 95% confidence intervals (CIs) of pressure ulcer associated with the use of statins.

RESULTS

Stroke patients who used statins had a reduced risk of pressure ulcers during the follow-up period (HR 0.74, 95% CI 0.71-0.78). The association between statin use and a reduced risk of poststroke pressure ulcers was significant in men (HR 0.73, 95% CI 0.68-0.78), women (HR 0.75, 95% CI 0.71-0.80), and people aged more than 50 years. Use of lovastatin, pravastatin, rosuvastatin, atrovastatin, fluvastatin, and simvastatin was associated with reduced poststroke pressure ulcers. There was a dose-dependent decrease in the frequency of pressure ulcers with increasing quantities of statins used, from 1 prescription to ≥3 prescriptions.

CONCLUSION

We raised the possibility that use of statins was associated with reduced risk of pressure ulcers in stroke patients. However, the potential beneficial effect associated with statins requires further validation using randomized clinical trials.

Possible mechanisms involved in the effect of the subchronic administration of rosuvastatin on endothelial function in rats with metabolic syndrome

Metabolic syndrome is a multifaceted condition associated with a greater risk of various disorders (e.g., diabetes and heart disease). In a rat model of metabolic syndrome, an acute in vitro application of rosuvastatin causes relaxation of aortic rings. Since the outcome of a subchronic rosuvastatin treatment is unknown, the present study explored its effect on acetylcholine-induced vasorelaxation of aortic rings from rats with metabolic syndrome. Animals were submitted to a 16-week treatment, including a standard diet, a cafeteria-style diet (CAF-diet), or a CAF-diet with daily rosuvastatin treatment (10 mg/kg). After confirming the development of metabolic syndrome in rats, aortic segments were extracted from these animals (those treated with rosuvastatin and untreated) and the acetylcholine-induced relaxant effect on the corresponding rings was evaluated. Concentration-response curves were constructed for this effect in the presence/absence of L-NAME, ODQ, KT 5823, 4-aminopyridine (4-AP), tetraethylammonium (TEA), apamin plus charybdotoxin, glibenclamide, indomethacin, clotrimazole, and cycloheximide pretreatment. Compared to rings from control rats, acetylcholine-induced vasorelaxation decreased in rings from animals with metabolic syndrome, and was maintained at a normal level in animals with metabolic syndrome plus rosuvastatin treatment. The effect of rosuvastatin was inhibited by L-NAME, ODQ, KT 5823, TEA, apamin plus charybdotoxin, but unaffected by 4-AP, glibenclamide, indomethacin, clotrimazole, or cycloheximide. In conclusion, the subchronic administration of rosuvastatin to rats with metabolic syndrome improved the acetylcholine-induced relaxant response, involving stimulation of the NO/cGMP/PKG/Ca2+-activated K+ channel pathway.

Mutual Influences between Nitric Oxide and Paraoxonase 1

One of the best consolidated paradigms in vascular pharmacology is that an uncontrolled excess of oxidizing chemical species causes tissue damage and loss of function in the endothelial and subendothelial layers. The fact that high-density lipoproteins play an important role in preventing such an imbalance is integrated into that concept, for which the expression and activity of paraoxonases is certainly crucial. The term paraoxonase (aryldialkyl phosphatase, EC 3.1.8.1) encompasses at least three distinct isoforms, with a wide variation in substrate affinity, cell and fluid localization, and biased expression of polymorphism. The purpose of this review is to determine the interactions that paraoxonase 1 has with nitric oxide synthase, its reaction product, nitric oxide (nitrogen monoxide, NO), and its derived reactive species generated in an oxidative medium, with a special focus on its pathological implications.

Oxidative stress in autosomal dominant polycystic kidney disease: player and/or early predictor for disease progression?

Autosomal dominant polycystic kidney disease (ADPKD), caused by mutations in PKD1 or PKD2 genes, is the most common hereditary renal disease. Renal manifestations of ADPKD are gradual cyst development and kidney enlargement ultimately leading to end-stage renal disease. ADPKD also causes extrarenal manifestations, including endothelial dysfunction and hypertension. Both of these complications are linked with reduced nitric oxide levels related to excessive oxidative stress (OS). OS, defined as disturbances in the prooxidant/antioxidant balance, is harmful to cells due to the excessive generation of highly reactive oxygen and nitrogen free radicals. Next to endothelial dysfunction and hypertension, there is cumulative evidence that OS occurs in the early stages of ADPKD. In the current review, we aim to summarize the cardiovascular complications and the relevance of OS in ADPKD and, more specifically, in the early stages of the disease. First, we will briefly introduce the link between ADPKD and the early cardiovascular complications including hypertension. Secondly, we will describe the potential role of OS in the early stages of ADPKD and its possible importance beyond the chronic kidney disease (CKD) effect. Finally, we will discuss some pharmacological agents capable of reducing reactive oxygen species and OS, which might represent potential treatment targets for ADPKD.

Innovations in asthma therapy: is there a role for inhaled statins?

INTRODUCTION

Asthma manifests as chronic airflow obstruction with persistent inflammation and airway hyperresponsiveness. The immunomodulatory and anti-inflammatory properties of the HMG-CoA reductase (HMGCR) inhibitors (a.k.a. statins), suggest a therapeutic role in chronic inflammatory lung diseases. However, despite positive laboratory investigations and promising epidemiological data, clinical trials using statins for the treatment of asthma have yielded conflicting results. Inadequate statin levels in the airway compartment could explain these findings. Areas covered: HMGCR is in the mevalonate (MA) pathway and MA signaling is fundamental to lung biology and asthma. This article will discuss clinical trials of oral statins in asthma, review lab investigations relevant to the systemic versus inhaled administration of statins, address the advantages and disadvantages of inhaled statins, and answer the question: is there a role for inhaled statins in the treatment of asthma? Expert commentary: If ongoing investigations show that oral administration of statins has no clear clinical benefits, then repurposing statins for delivery via inhalation is a logical next step. Inhalation of statins bypasses first-pass metabolism by the liver, and therefore, allows for delivery of significantly lower doses to the airways at greater potency. Statins could become the next major class of novel inhalers for the treatment of asthma.

Endothelial Progenitor Cells in Heart Failure: an Authentic Expectation for Potential Future Use and a Lack of Universal Definition

Congestive heart failure (CHF) is a prevalent disease (especially among the elderly) with high mortality and morbidity rates. The pathological hallmark of CHF is a loss of cardiomyocytes leading to cardiac fibrosis and dysfunctional cardiac remodeling, which culminates in organ failure. Endothelial progenitor cells (EPCs) are bone marrow-derived cells that contribute to maintenance of the integrity of endothelial wall and protect ischemic myocardium through forming new blood vessels (vasculogenesis) or proliferation of pre-existing vasculature (angiogenesis). Despite its potential, little is known about EPCs and their function in CHF. Here, we define EPC and its role in health and CHF, highlighting their contributions as a cornerstone in the maintenance of a healthy endothelium. Thereafter, we explore the behavior and relevance of EPCs in the pathophysiology of CHF, their prognostic importance, and possible utilization of EPCs as therapy for CHF. Lastly, the restrictions surrounding the use of EPCs in clinical practice will be discussed.

Simvastatin reduces vaso-occlusive pain in sickle cell anaemia: a pilot efficacy trial

Sickle cell anaemia (SCA) is a progressive vascular disease characterized by episodic vaso-occlusive pain. Despite the broad impact of inflammation on acute and chronic clinical manifestations of SCA, no directed anti-inflammatory therapies currently exist. Statins are cholesterol-lowering agents shown to confer protection from vascular injury by suppressing inflammation. We previously documented a reduction in soluble biomarkers of inflammation in patients with sickle cell disease treated with simvastatin. To determine the potential clinical efficacy of simvastatin, we treated 19 SCA patients with single daily dose simvastatin for 3 months and assessed changes from baseline in the frequency and intensity of diary-reported pain and levels of circulating nitric oxide metabolites (NOx), high sensitivity C-reactive protein (hs-CRP), vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), ICAM-3, E-selectin, and vascular endothelial growth factor (VEGF). Treatment with simvastatin resulted in a significant reduction in the frequency of pain (P = 0·0003), oral analgesic use (P = 0·003) and circulating hs-CRP (P = 0·003), soluble (s)E-selectin (P = 0·01), sICAM-1 (P = 0·02), sICAM-3 (P = 0·02) and sVEGF (P = 0·01). Simvastatin had no effect on pain intensity or levels of NOx, sP-selectin and sVCAM-1. The observed reductions in pain rate and markers of inflammation were greatest in subjects receiving hydroxycarbamide (HC), suggesting a synergistic effect of simvastatin. These results provide preliminary clinical data to support a larger trial of simvastatin in SCA.

Atorvastatin does not protect against ischemia-reperfusion damage in cholestatic rat livers

BACKGROUND

Extrahepatic cholestasis sensitizes the liver to ischemia/reperfusion (I/R) injury during surgery for perihilar cholangiocarcinoma. It is associated with pre-existent sterile inflammation, microvascular perfusion defects, and impaired energy status. Statins have been shown to protect against I/R injury in normal and steatotic mouse livers. Therefore, the hepatoprotective properties of atorvastatin were evaluated in a rat model of cholestatic I/R injury.

METHODS

Male Wistar rats were subjected to 70% hepatic ischemia (during 30 min) at 7 days after bile duct ligation. Rats were randomized to atorvastatin treatment or vehicle-control in three test arms: (1) oral treatment with 5 mg/kg during 7 days after bile duct ligation; (2) intravenous treatment with 2.5, 5, or 7.5 mg/kg at 24 h before ischemia; and (3) intravenous treatment with 5 mg/kg at 30 min before ischemia. Hepatocellular damage was assessed by plasma alanine aminotransferase (ALT) and histological necrosis.

RESULTS

I/R induced severe hepatocellular injury in the cholestatic rat livers (~10-fold increase in ALT at 6 h after I/R and ~30% necrotic areas at 24 h after I/R). Both oral and intravenous atorvastatin treatment decreased ALT levels before ischemia. Intravenous atorvastatin treatment at 5 mg/kg at 24 h before ischemia was the only regimen that reduced ALT levels at 6 h after reperfusion, but not at 24 h after reperfusion. None of the tested regimens were able to reduce histological necrosis at 24 h after reperfusion.

CONCLUSION

Pre-treatment with atorvastatin did not protect cholestatic livers from hepatocellular damage after I/R. Clinical studies investigating the role of statins in the protection against hepatic I/R injury should not include cholestatic patients with perihilar cholangiocarcinoma. These patients require (pharmacological) interventions that specifically target the cholestasis-associated hepatopathology.

The Top 12 Advances in Vascular Medicine

In the past decade, impressive strides have been made in the diagnosis and management of atherosclerotic, aneurysmal, and thromboembolic diseases, thanks in large part to the explosive growth in both vascular biology and clinical vascular medicine. We review what we consider to be the top 12 advances in this field: the discovery of nitric oxide, the metabolic syndrome, new thrombophilic disorders, therapeutic angiogenesis, endoluminal treatment of chronic venous disease, and a variety of drugs, including sildenafil, cilostazol, low-molecular-weight heparins, oral direct thrombin inhibitors, clopidogrel, statins, and angiotensin-converting enzyme inhibitors and angiotensin-receptor blocking agents.

Lovastatin exerts protective effects on endothelial cells via upregulation of PTK2B

Statins are HMG-CoA reductase inhibitors that are used to decrease the blood levels of low-density lipoprotein (LDL). In addition, they have been shown to exert pleiotropic protective effects in the absence of LDL-lowering activity. The present study investigated the effects of lovastatin on global gene expression in human umbilical vein endothelial cells (HUVECs), in order to further explore its ability to protect against oxidized (ox)-LDL-induced cytotoxicity. HUVECs were treated with lovastatin for 2–24 h, and gene expression patterns were analyzed using cDNA microarrays. The results suggested that numerous genes were regulated by lovastatin, including certain genes associated with cell survival, such as PTK2B, BCL2 and MAP3K3. In particular, PTK2B, which has been shown to exert anti-apoptotic effects against ox-LDL-induced cell injury, was upregulated by lovastatin. Knockdown of PTK2B was able to attenuate ox-LDL-induced cell injury, and this was associated with decreased levels of phosphorylated-AKT and eNOS, and inhibition of mitochondrial-dependent apoptosis. In conclusion, the results of the present study suggested that lovastatin protects against ox-LDL-induced cell injury, potentially via the upregulation of PTK2B, which regulates the anti-apoptosis signaling pathway.

In situ eNOS/NO up-regulation-a simple and effective therapeutic strategy for diabetic skin ulcer

Decreased nitric oxide (NO) synthesis and increased NO consumption in diabetes induces the inadequate blood flow to tissues that is primarily responsible for the pathogenesis and refractoriness of diabetic skin ulcers. The present study proposed a simple and effective therapeutic strategy for diabetic skin ulcers—in situ up-regulation of endothelial nitric oxide synthase (eNOS) expression and NO synthesis by statin-loaded tissue engineering scaffold (TES). In vitro experiments on human umbilical vein endothelial cells indicated that the statin-loaded TES relieved the high-glucose induced decrease in cell viability and promoted NO synthesis under high-glucose conditions. In a rat model of diabetes, the statin-loaded TES promoted eNOS expression and NO synthesis in/around the regenerated tissues. Subsequently, accelerated vascularization and elevated blood supply were observed, followed by rapid wound healing. These findings suggest that the in situ up-regulation of eNOS/NO by a statin-loaded TES may be a useful therapeutic method for intractable diabetic skin wounds.

Efficacy of lycopene on modulation of renal antioxidant enzymes, ACE and ACE gene expression in hyperlipidaemic rats

INTRODUCTION

We aimed to evaluate the efficacy of lycopene on renal tissue antioxidant enzymes and angiotensin converting enzyme (ACE) gene expression and serum activity in diet-induced hyperlipidaemia.

METHODS

Thirty-two female Wistar albino rats (200-250 g weight), 5-6 months of age, were randomly selected and divided into four groups. Group I received normal diet; group II received 24 g high fat diet/100 g of daily diet; group III received 24 g high fat diet/100 g daily diet and 200 ml of lycopene extract (twice a week) for 8 weeks; and group IV received 200 ml oral lycopene extract twice a week for 8 weeks.

RESULTS

A marked increase was observed in plasma urea and creatinine levels, serum C-reactive protein, kidney weight, tissue renal malonyldialdehyde level, ACE gene expression and serum level, while a decrease catalase level among hyperlipidaemic rats was observed. Histologically, interstitial inflammation and proliferation was seen. Lycopene supplementation significantly decreased plasma urea and creatinine, serum ACE, renal tissue malonyldialdehyde level and C-reactive protein level, while it increased tissue antioxidant enzymes level and total protein. Tissue inflammation and proliferation was improved.

CONCLUSIONS

This finding suggests that supplementation of lycopene is effective for renal antioxidant enzymes, ACE gene expression and ACE serum level in hyperlipidaemic rats.

Biomarkers and surrogate endpoints in kidney disease

Kidney disease and its related comorbidities impose a large public health burden. Despite this, the number of clinical trials in nephrology lags behind many other fields. An important factor contributing to the relatively slow pace of nephrology trials is that existing clinical endpoints have significant limitations. "Hard" endpoints for chronic kidney disease, such as progression to end-stage renal disease, may not be reached for decades. Traditional biomarkers, such as serum creatinine in acute kidney injury, may lack sensitivity and predictive value. Finding new biomarkers to serve as surrogate endpoints is therefore an important priority in kidney disease research and may help to accelerate nephrology clinical trials. In this paper, I first review key concepts related to the selection of clinical trial endpoints and discuss statistical and regulatory considerations related to the evaluation of biomarkers as surrogate endpoints. This is followed by a discussion of the challenges and opportunities in developing novel biomarkers and surrogate endpoints in three major areas of nephrology research: acute kidney injury, chronic kidney disease, and autosomal dominant polycystic kidney disease.

Biodegradable Polymers Influence the Effect of Atorvastatin on Human Coronary Artery Cells

Drug-eluting stents (DES) have reduced in-stent-restenosis drastically. Yet, the stent surface material directly interacts with cascades of biological processes leading to an activation of cellular defense mechanisms. To prevent adverse clinical implications, to date almost every patient with a coronary artery disease is treated with statins. Besides their clinical benefit, statins exert a number of pleiotropic effects on endothelial cells (ECs). Since maintenance of EC function and reduction of uncontrolled smooth muscle cell (SMC) proliferation represents a challenge for new generation DES, we investigated the effect of atorvastatin (ATOR) on human coronary artery cells grown on biodegradable polymers. Our results show a cell type-dependent effect of ATOR on ECs and SMCs. We observed polymer-dependent changes in IC50 values and an altered ATOR-uptake leading to an attenuation of statin-mediated effects on SMC growth. We conclude that the selected biodegradable polymers negatively influence the anti-proliferative effect of ATOR on SMCs. Hence, the process of developing new polymers for DES coating should involve the characterization of material-related changes in mechanisms of drug actions.

Advances in treatment strategies for ischemia reperfusion injury

INTRODUCTION

Ischemia-reperfusion injury (IRI) involves a complex sequence of events and limits the outcome of various surgical interventions. Clinical trials, based on the data of experimental models, aim to prove whether a pharmacological or technical approach could be suitable to provide a beneficial effect in humans. Due to the complexity of IRI, few pharmacological treatments have been investigated in clinical Phase III.

AREAS COVERED

In this review we report clinical trials that test specific drugs in clinical trials of organ transplantation. These studies form part of Phase II trials and examine the administration of caspase inhibitors, P-selectin antagonist or an antioxidant component in order to attenuate cold IRI during transplantation. Moreover, we provide a brief description of drugs tested on trials of different clinical situations associated to IRI, such as the coronary artery bypass graft surgery and percutaneous coronary intervention.

EXPERT OPINION

Future clinical trials could be centered on the application of techniques suitable for organs with increased vulnerability toward IRI. Furthermore, the standardization of reliable biomarkers and a careful estimation of the impact of high risk factors may be the key in order to achieve a more critical evaluation of the obtained results.

The Arginine/ADMA Ratio Is Related to the Prevention of Atherosclerotic Plaques in Hypercholesterolemic Rabbits When Giving a Combined Therapy with Atorvastatine and Arginine

Supplementation with arginine in combination with atorvastatin is more efficient in reducing the size of an atherosclerotic plaque than treatment with a statin or arginine alone in homozygous Watanabe heritable hyperlipidemic (WHHL) rabbits. We evaluated the mechanism behind this feature by exploring the role of the arginine/asymmetric dimethylarginine (ADMA) ratio, which is the substrate and inhibitor of nitric oxide synthase (NOS) and thereby nitric oxide (NO), respectively. Methods: Rabbits were fed either an arginine diet (group A, n = 9), standard rabbit chow plus atorvastatin (group S, n = 8), standard rabbit chow plus an arginine diet with atorvastatin (group SA, n = 8) or standard rabbit chow (group C, n = 9) as control. Blood was sampled and the aorta was harvested for topographic and histological analysis. Plasma levels of arginine, ADMA, cholesterol and nitric oxide were determined and the arginine/ADMA ratio was calculated. Results: The decrease in ADMA levels over time was significantly correlated to fewer aortic lesions in the distal aorta and total aorta. The arginine/ADMA ratio was correlated to cholesterol levels and decrease in cholesterol levels over time in the SA group. A lower arginine/ADMA ratio was significantly correlated to lower NO levels in the S and C group. Discussion: A balance between arginine and ADMA is an important indicator in the prevention of the development of atherosclerotic plaques.

Statin-Induced Increases in Atrophy Gene Expression Occur Independently of Changes in PGC1α Protein and Mitochondrial Content

One serious side effect of statin drugs is skeletal muscle myopathy. Although the mechanism(s) responsible for statin myopathy remains to be fully determined, an increase in muscle atrophy gene expression and changes in mitochondrial content and/or function have been proposed to play a role. In this study, we examined the relationship between statin-induced expression of muscle atrophy genes, regulators of mitochondrial biogenesis, and markers of mitochondrial content in slow- (ST) and fast-twitch (FT) rat skeletal muscles. Male Sprague Dawley rats were treated with simvastatin (60 or 80 mg·kg^-1·day^-1) or vehicle control via oral gavage for 14 days. In the absence of overt muscle damage, simvastatin treatment induced an increase in atrogin-1, MuRF1 and myostatin mRNA expression; however, these were not associated with changes in peroxisome proliferator gamma co-activator 1 alpha (PGC-1α) protein or markers of mitochondrial content. Simvastatin did, however, increase neuronal nitric oxide synthase (nNOS), endothelial NOS (eNOS) and AMPK α-subunit protein expression, and tended to increase total NOS activity, in FT but not ST muscles. Furthermore, simvastatin induced a decrease in β-hydroxyacyl CoA dehydrogenase (β-HAD) activity only in FT muscles. These findings suggest that the statin-induced activation of muscle atrophy genes occurs independent of changes in PGC-1α protein and mitochondrial content. Moreover, muscle-specific increases in NOS expression and possibly NO production, and decreases in fatty acid oxidation, could contribute to the previously reported development of overt statin-induced muscle damage in FT muscles.

Statin therapy does not affect the radiographic and clinical profile of patients with TIA and minor stroke

BACKGROUND AND PURPOSE

Acute statin therapy improves neurologic outcome and diminishes infarct growth in animal models of stroke. Clinical studies suggest that premorbid and early statin use is associated with improved outcome after major stroke. We studied the association between statin therapy and radiographic and clinical outcomes in patients with high-risk TIA and minor stroke.

MATERIALS AND METHODS

Patients with high-risk TIA and minor stroke (NIHSS ≤3) were prospectively enrolled within 24 hours of symptom onset. Patients were followed clinically for 3 months, and a subset had a repeat MR imaging at 90 days.

RESULTS

Of 418 patients, 23% were prescribed statins before their stroke. Statins were continued in 20% and initiated in 42%. Patients on prior statin therapy were older and more hypertensive, treated with aspirin, and more likely to have symptomatic carotid disease compared with those not on statin. Adjusting for these differences, prior statin treatment was not associated with DWI positivity (adjusted OR = 1.3; 95% CI, 0.77-2.1; P = .32) or smaller median baseline infarct volume, 1.1 mL (interquartile range = 4) versus 1 mL (interquartile range = 2.5; P = .56). Early or continued treatment with statins did not improve the risk of clinical deterioration (adjusted OR = 0.66; 95% CI, 0.27-1.6; P = .35) or poor functional outcome at 3 months (adjusted OR = 0.66; 95% CI, 0.35-1.24; P = .19).

CONCLUSIONS

Prestroke or early-stroke statin therapy was not associated with a reduction in the number of DWI lesions, infarct volume, or improved clinical or functional outcome at 3 months. The effect of acute statin treatment in patients with ischemic stroke/TIA remains unclear and needs further investigation.

Atorvastatin treatment improves endothelial function through endothelial progenitor cells mobilization in ischemic heart failure patients

OBJECTIVE

Endothelial function is an independent predictor of prognosis in heart failure (HF) subjects. Statins, beyond their lipid lowering role, exert beneficial effect in patients with atherosclerosis. In the present study we examined the impact of low and intermediate dose atorvastatin treatment on endothelial function, bone marrow-derived endothelial progenitor cells (EPC) mobilization and inflammatory status according to HF patient status.

METHODS

We studied the effect of 4 weeks administration of atorvastatin in 26 patients with ischemic HF. The study was carried out on two separate arms, one with atorvastatin 40 mg/d and one with atorvastatin 10 mg/d (randomized, double-blind, cross-over design). The number of circulating CD34(+)/CD133(+)/KDR(+) EPCs was evaluated by flow cytometry. Endothelial function was evaluated by flow mediated dilation (FMD) in the brachial artery. Serum levels of tumor necrosis factor alpha (TNF-α) were measured by ELISA.

RESULTS

Treatment with atorvastatin 40 mg/d significantly increased circulating EPC (p = 0.002), FMD (p = 0.001) and reduced TNF-α (p = 0.01) compared to baseline. Similarly, treatment with atorvastatin 10 mg/day increased circulating EPC (p = 0.01), FMD (p = 0.08) and reduced TNF-α (p = 0.01) compared to baseline. Interestingly, with 40 mg/day atorvastatin treatment the increase in EPC was higher in subjects categorized as NYHA class II compared to subjects categorized as NYHA class III (p = 0.03).

CONCLUSIONS

Our results confirmed the distinct impact of atorvastatin treatment on the restoration of endothelial function due to EPC mobilization in ischemic HF subjects. Moreover, these findings provide the potential clinical significance of EPC status monitoring to individualize treatment in HF subjects.

Effect of pravastatin on total kidney volume, left ventricular mass index, and microalbuminuria in pediatric autosomal dominant polycystic kidney disease

BACKGROUND AND OBJECTIVES

In autosomal dominant polycystic kidney disease (ADPKD), progressive kidney cyst formation commonly leads to ESRD. Because important manifestations of ADPKD may be evident in childhood, early intervention may have the largest effect on long-term outcome. Statins are known to slow progressive nephropathy in animal models of ADPKD. This randomized double-blind placebo-controlled phase III clinical trial was conducted from 2007 to 2012 to assess the effect of pravastatin on height-corrected total kidney volume (HtTKV) and left ventricular mass index (LVMI) by magnetic resonance imaging (MRI) and urine microalbumin excretion (UAE) in children and young adults with ADPKD.

DESIGNS, SETTING, PARTICIPANTS, & MEASUREMENTS

There were 110 pediatric participants with ADPKD and normal kidney function receiving lisinopril who were randomized to treatment with pravastatin or placebo for a 3-year period with evaluation at 0, 18, and 36 months. The primary outcome variable was a ≥ 20% change in HtTKV, LVMI, or UAE over the study period.

RESULTS

Ninety-one participants completed the 3-year study (83%). Fewer participants receiving pravastatin achieved the primary endpoint compared with participants receiving placebo (69% versus 88%; P=0.03). This was due primarily to a lower proportion reaching the increase in HtTKV (46% versus 68%; P=0.03), with similar findings observed between study groups for LVMI (25% versus 38%; P=0.18) and UAE (47% versus 39%; P=0.50). The percent change in HtTKV adjusted for age, sex, and hypertension status over the 3-year period was significantly decreased with pravastatin (23% ± 3% versus 31% ± 3%; P=0.02).

CONCLUSIONS

Pravastatin is an effective agent to slow progression of structural kidney disease in children and young adults with ADPKD. These findings support a role for early intervention with pravastatin in this condition.

Prevention of arterial stiffening by using low-dose atorvastatin in diabetes is associated with decreased malondialdehyde

Introduction

Without affecting the lipid profile, a low-dose treatment with atorvastatin contributes to the reduction of oxidative stress, inflammation, and adverse cardiovascular events in diabetes. In this study, we investigated whether low-dose atorvastatin exerts any beneficial effect on vascular dynamics in streptozotocin (STZ)-induced diabetes in male Wistar rats.

Methods

Diabetes was induced using a single tail-vein injection of STZ at 55 mg kg⁻¹. The diabetic rats were treated daily with atorvastatin (10 mg kg⁻¹ by oral gavage) for 6 weeks. They were also compared with untreated age-matched diabetic controls. Arterial wave reflection was derived using the impulse response function of the filtered aortic input impedance spectra. A thiobarbituric acid reactive substances measurement was used to estimate the malondialdehyde content.

Results

The high plasma level of total cholesterol in the diabetic rats did not change in response to this low-dose treatment with atorvastatin. Atorvastatin resulted in a significant increase of 15.4% in wave transit time and a decrease of 33.5% in wave reflection factor, suggesting that atorvastatin may attenuate the diabetes-induced deterioration in systolic loads imposed on the heart. This was in parallel with its lowering of malondialdehyde content in plasma and aortic walls in diabetes. Atorvastatin therapy also prevented the diabetes-related cardiac hypertrophy, as evidenced by the diminished ratio of left ventricular weight to body weight.

Conclusion

These findings indicate that low-dose atorvastatin might protect diabetic vasculature against diabetes-associated deterioration in aorta stiffness and cardiac hypertrophy, possibly through its decrease of lipid oxidation-derived malondialdehyde.

Rosuvastatin-regulated post-translational phosphoproteome in human umbilical vein endothelial cells

Statins, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, are widely prescribed as cholesterol-lowering drugs. Statins have recently been found to have pleiotropic effects that are independent of their lipid-lowering properties. Phosphorylation of serine, threonine, and tyrosine residues of functional proteins are considered to be important in the endothelial signaling cascade. In this study, protein phosphorylation status in human umbilical vein endothelial cells (ECs) after rosuvastatin treatment was examined. The proteins were collected from rosuvastatin-treated ECs and then the phosphorylated peptides purified by a Fe(3+)-immobilized metal-affinity chromatography bead system were examined by liquid chromatography-tandem mass spectrometry analysis. Alterations of the phosphorylation status of proteins were noticed after rosuvastatin treatment. There were 277 and 530 phosphorylated proteins identified from the control and rosuvastatin-treated ECs, respectively. Among those proteins, T78, in addition to S156 of the Ras-GTPase-activating protein, was phosphorylated after rosuvastatin treatment. Rosuvastatin reduced the phosphorylation of Y455 in HSP90 protein. Decreased phosphorylation of T211 with a concurrent increase in the T291 phosphorylation of Akt1 was observed under rosuvastatin treatment. Increased S633 phosphorylation was detected in endothelial nitric oxide synthase. Western blot analysis further showed an earlier and greater S633 phosphorylation than that of S1177 in endothelial nitric oxide synthase after rosuvastatin treatment. Changes in the phosphorylation status of these proteins may alter the protein's function and affect endothelial physiology. The current study provides new insights leading to a better understanding of the pleiotropic effects of statins on the vascular system.

Targeting reactive nitrogen species: a promising therapeutic strategy for cerebral ischemia-reperfusion injury

Ischemic stroke accounts for nearly 80% of stroke cases. Recanalization with thrombolysis is a currently crucial therapeutic strategy for re-building blood supply, but the thrombolytic therapy often companies with cerebral ischemia-reperfusion injury, which are mediated by free radicals. As an important component of free radicals, reactive nitrogen species (RNS), including nitric oxide (NO) and peroxynitrite (ONOO(-)), play important roles in the process of cerebral ischemia-reperfusion injury. Ischemia-reperfusion results in the production of nitric oxide (NO) and peroxynitrite (ONOO(-)) in ischemic brain, which trigger numerous molecular cascades and lead to disruption of the blood brain barrier and exacerbate brain damage. There are few therapeutic strategies available for saving ischemic brains and preventing the subsequent brain damage. Recent evidence suggests that RNS could be a therapeutic target for the treatment of cerebral ischemia-reperfusion injury. Herein, we reviewed the recent progress regarding the roles of RNS in the process of cerebral ischemic-reperfusion injury and discussed the potentials of drug development that target NO and ONOO(-) to treat ischemic stroke. We conclude that modulation for RNS level could be an important therapeutic strategy for preventing cerebral ischemia-reperfusion injury.

ICRP publication 118: ICRP statement on tissue reactions and early and late effects of radiation in normal tissues and organs--threshold doses for tissue reactions in a radiation protection context

This report provides a review of early and late effects of radiation in normal tissues and organs with respect to radiation protection. It was instigated following a recommendation in Publication 103 (ICRP, 2007), and it provides updated estimates of 'practical' threshold doses for tissue injury defined at the level of 1% incidence. Estimates are given for morbidity and mortality endpoints in all organ systems following acute, fractionated, or chronic exposure. The organ systems comprise the haematopoietic, immune, reproductive, circulatory, respiratory, musculoskeletal, endocrine, and nervous systems; the digestive and urinary tracts; the skin; and the eye. Particular attention is paid to circulatory disease and cataracts because of recent evidence of higher incidences of injury than expected after lower doses; hence, threshold doses appear to be lower than previously considered. This is largely because of the increasing incidences with increasing times after exposure. In the context of protection, it is the threshold doses for very long follow-up times that are the most relevant for workers and the public; for example, the atomic bomb survivors with 40-50years of follow-up. Radiotherapy data generally apply for shorter follow-up times because of competing causes of death in cancer patients, and hence the risks of radiation-induced circulatory disease at those earlier times are lower. A variety of biological response modifiers have been used to help reduce late reactions in many tissues. These include antioxidants, radical scavengers, inhibitors of apoptosis, anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, growth factors, and cytokines. In many cases, these give dose modification factors of 1.1-1.2, and in a few cases 1.5-2, indicating the potential for increasing threshold doses in known exposure cases. In contrast, there are agents that enhance radiation responses, notably other cytotoxic agents such as antimetabolites, alkylating agents, anti-angiogenic drugs, and antibiotics, as well as genetic and comorbidity factors. Most tissues show a sparing effect of dose fractionation, so that total doses for a given endpoint are higher if the dose is fractionated rather than when given as a single dose. However, for reactions manifesting very late after low total doses, particularly for cataracts and circulatory disease, it appears that the rate of dose delivery does not modify the low incidence. This implies that the injury in these cases and at these low dose levels is caused by single-hit irreparable-type events. For these two tissues, a threshold dose of 0.5Gy is proposed herein for practical purposes, irrespective of the rate of dose delivery, and future studies may elucidate this judgement further.

Relaxation of rat thoracic aorta by fibrate drugs correlates with their potency to disturb intracellular calcium of VSMCs

Phenotypic modifications of vascular smooth muscle cells (VSMCs) contribute to pathological changes in atherosclerosis where modulation of intracellular calcium plays an important role. In this study, three fibrate drugs, namely gemfibrozil (Gem), fenofibric acid (Fa) and bezafibrate (Beza), were revealed to relax thoracic aorta associated with their potency to reduce intracellular calcium ([Ca²⁺]i) in cultured VSMCs. Relaxation effect of Gem, Fa and Beza was assayed on precontracted rat aortic rings. [Ca²⁺]i level in VSMCs following addition of these fibrates was measured by laser scanning confocal microscopy or flow cytometry. Resultantly, three fibrates showed activity for vasodilation with potency order of Gem>Fa>Beza. Sustained potent reduction of [Ca²⁺]i was observed with Gem 50mg/L and mild reduction with Fa 400-600mg/L, while no effect had been detected for Beza under our current system. Thus, the potency of these fibrates to relax aortic rings correlate well with their effect on [Ca²⁺]i reduction, strongly implicating an underlying causal relationship. Considering that Gem potently reduces [Ca²⁺]i in its clinical concentration range, this study suggests an insight to in situ pharmacological effects of anti-atherosclerosis and clinical toxicity risk.

Potential role of statins on wound healing: review of the literature

Wound healing is a dynamic and complex biological process, which requires coordinated events including haemostasis, inflammation, proliferation, revascularisation and remodelling. Impaired wound healing is a common problem that occurs in both community and hospital settings. Various experimental and clinical studies have evaluated different modalities for the treatment of topical wounds, such as sugar, antibiotics, honey and phytotherapies; also statins have diverse pleiotropic effects that have been suggested to be useful to improve wound healing. Data derived from both animal and human studies showed that statins especially atorvastatin, simvastatin and pravastatin can accelerate the wound-healing process. However, further high-quality and evidence-based studies are needed to address the best statin drug, appropriate dose, the best administration route, duration of treatment and to determine correlation between pleiotropic effects of statins and their probable clinical benefits.

Heat shock protein 90 mediates anti-apoptotic effect of diazoxide by preventing the cleavage of Bid in hypothermic preservation rat hearts

BACKGROUND

Successful organ preservation is the premise for clinical organ transplantation. The present study investigated whether heat shock protein 90 (Hsp90) is important in the anti-apoptotic effect of diazoxide in hypothermic preservation rat hearts.

METHODS

Isolated rat hearts were preserved in Celsior solution, with or without diazoxide, for 3 to 9 hours, followed by 60 minutes of reperfusion. Cell apoptosis was assessed by terminal deoxynucleotide transferase-mediated deoxy uridine triphosphate nick-end labeling. The left ventricular developed pressure (LVDP) was recorded. Expression of Hsp90 protein and cleavage of Bid were detected by Western blot and polymerase chain reaction.

RESULTS

After hypothermic preservation for 3 to 9 hours, the LVDP recovery rate significantly decreased and cardiomyocyte apoptosis index increased in a time-dependent manner. When compared with the 9-hour preservation group, Celsior solution supplemented with diazoxide significantly enhanced the LVDP recovery rate and decreased the apoptosis index. The cleavage of Bid increased after 9 hours of hypothermic preservation, which was inhibited by Celsior solution supplemented with diazoxide. Hypothermic preservation of rat hearts for 9 hours decreased the expression of Hsp90, whereas diazoxide supplementation significantly increased the expression of Hsp90. The Hsp90 inhibitor 17-allylamino-17-demethoxy-geldanamycin inhibited the diazoxide-induced decrease in cleavage of Bid, improvement of cardiac function, and decrease of apoptosis. Hsp90 inhibitor had no effect on the diazoxide-induced increase of total Cx43 protein expression in hearts preserved 9 hours, but inhibited the diazoxide-induced increase of mitochondrial Cx43 protein level.

CONCLUSION

Hsp90 might mediate diazoxide-induced cardioprotection against apoptosis in hypothermic preservation heart by preventing the cleavage of Bid.

Simvastatin augments the efficacy of therapeutic angiogenesis induced by bone marrow-derived mesenchymal stem cells in a murine model of hindlimb ischemia

Many studies showed beneficial effects of either statin or bone marrow-derived mesenchymal stem cells (MSC) treatment in ischemic disease. In an attempt to further improve postischemic tissue repair, we investigated the effect of a local administration of MSC, in the presence or not of low-dose simvastatin, on angiogenesis and functional recovery in a mouse model of hindlimb ischemia. In vitro, the proliferation, migration, apoptosis, and tube formation of bone marrow MSC derived from transgenic mice expressing green fluorescent protein (GFP) were detected in the presence or not of 0.01 μmol/l simvastatin, respectively. In vivo, immediately after hindlimb ischemia, the mice were divided into four groups, namely control, MSC, statin, and statin-MSC, and received a single local injection of MSC (2×10(6) cells) and/or a repeated gavages' administration of simvastatin (0.2 mg/kg) for 21 days. The blood flow was measured by laser Doppler imaging, the capillary density was detected by alkaline phosphatase staining and, the MSC differentiation was assessed by immunofluorescent staining at 21 days after the ischemia. In vitro, the MSC proliferation rate, migration ability and tube formation number were increased significantly in simvastatin group relative to control group. Whereas, the H2O2 induced-apoptosis was inhibited significantly in simvastatin group relative to control group. In vivo, hindlimb blood reperfusion was significantly improved (MSC 0.55±0.08, statin 0.57±0.05, vs. control 0.47±0.07, P<0.05) and capillary density was obviously higher at day 21 post-ischemia by Laser Doppler Imaging in the MSC group and the Statin group when compared with control group. The combined use of statin and MSC further improved revascularization (perfusion ratio of 0.70±0.09; P<0.001 verse other groups) and resulted in the highest capillary density (P<0.05 vs. all other groups). GFP-labeled transplanted cells were more frequently observed in the Statin-MSC group than in the MSC group (6.8±0.5-3.1±0.7, P<0.05). Low-dose simvastatin could act in a synergistic way with MSC to potentiate the functional neovascularization in a mouse model of hind limb ischemia.

Granulocyte-CSF induced inflammation-associated cardiac thrombosis in iron loading mouse heart and can be attenuated by statin therapy

Background

Granulocyte colony-stimulating factor (G-CSF), a hematopoietic cytokine, was recently used to treat patients of acute myocardial infarction with beneficial effect. However, controversy exists as some patients developed re-stenosis and worsened condition post G-CSF delivery. This study presents a new disease model to study G-CSF induced cardiac thrombosis and delineate its possible mechanism. We used iron loading to mimic condition of chronic cardiac dysfunction and apply G-CSF to mice to test our hypothesis.

Methods and Results

Eleven out of fifteen iron and G-CSF treated mice (I+G) showed thrombi formation in the left ventricular chamber with impaired cardiac function. Histological analysis revealed endothelial fibrosis, increased macrophage infiltration and tissue factor expression in the I+G mice hearts. Simvastatin treatment to I+G mice attenuated their cardiac apoptosis, iron deposition, and abrogated thrombus formation by attenuating systemic inflammation and leukocytosis, which was likely due to the activation of pAKT activation. However, thrombosis in I+G mice could not be suppressed by platelet receptor inhibitor, tirofiban.

Conclusions

Our disease model demonstrated that G-CSF induces cardiac thrombosis through an inflammation-thrombosis interaction and this can be attenuated via statin therapy. Present study provides a mechanism and potential therapy for G-CSF induced cardiac thrombosis.