Effects of pitavastatin versus atorvastatin on the peripheral endothelial progenitor cells and vascular endothelial growth factor in high-risk patients: a pilot prospective, double-blind, randomized study

Endothelial progenitor cells as biomarkers of diabetes-related cardiovascular complications

Diabetes mellitus (DM) constitutes a chronic metabolic disease characterized by elevated levels of blood glucose which can also lead to the so-called diabetic vascular complications (DVCs), responsible for most of the morbidity, hospitalizations and death registered in these patients. Currently, different approaches to prevent or reduce DM and its DVCs have focused on reducing blood sugar levels, cholesterol management or even changes in lifestyle habits. However, even the strictest glycaemic control strategies are not always sufficient to prevent the development of DVCs, which reflects the need to identify reliable biomarkers capable of predicting further vascular complications in diabetic patients. Endothelial progenitor cells (EPCs), widely known for their potential applications in cell therapy due to their regenerative properties, may be used as differential markers in DVCs, considering that the number and functionality of these cells are affected under the pathological environments related to DM. Besides, drugs commonly used with DM patients may influence the level or behaviour of EPCs as a pleiotropic effect that could finally be decisive in the prognosis of the disease. In the current review, we have analysed the relationship between diabetes and DVCs, focusing on the potential use of EPCs as biomarkers of diabetes progression towards the development of major vascular complications. Moreover, the effects of different drugs on the number and function of EPCs have been also addressed.

Angiogenesis induction as a key step in cardiac tissue Regeneration: From angiogenic agents to biomaterials

Cardiovascular diseases are the leading cause of death worldwide. After myocardial infarction, the vascular supply of the heart is damaged or blocked, leading to the formation of scar tissue, followed by several cardiac dysfunctions or even death. In this regard, induction of angiogenesis is considered as a vital process for supplying nutrients and oxygen to the cells in cardiac tissue engineering. The current review aims to summarize different approaches of angiogenesis induction for effective cardiac tissue repair. Accordingly, a comprehensive classification of induction of pro-angiogenic signaling pathways through using engineered biomaterials, drugs, angiogenic factors, as well as combinatorial approaches is introduced as a potential platform for cardiac regeneration application. The angiogenic induction for cardiac repair can enhance patient treatment outcomes and generate economic prospects for the biomedical industry. The development and commercialization of angiogenesis methods often involves collaboration between academic institutions, research organizations, and biomedical companies.

Hyperlipidemia attenuates the mobilization of endothelial progenitor cells induced by acute myocardial ischemia via VEGF/eNOS/NO/MMP-9 pathway

This study aims to explore the role of hyperlipidemia in the mobilization of bone marrow (BM) endothelial progenitor cells (EPCs) induced by acute myocardial ischemia (AMI). To establish the hyperlipidemia complicated with AMI (HL-AMI) model, SD rats were intragastrically administered the high-fat emulsion for 4 weeks. Then their left anterior descending arteries were ligated. Rats in each group were randomly subdivided into seven subgroups. During 1st ~ 7th day following AMI modeling, rats in 1st ~ 7th subgroups were selected to be phlebotomized from their celiac artery after being anesthetized by pentobarbitone in turn. The quantity of circulating EPCs (CEPCs) was detected by flow cytometry, the expression of VEGF, eNOS, NO, MMP-9 in myocardial tissue was analyzed by western blot, and their plasma level was assayed by ELISA. Dynamic curves were plotted using these data. Within 7 days following AMI, compared with the AMI rats, in the HL-AMI rats, the myocardial infarct size, the plasma activity of CK, CK-MB, and the collagen deposition all remained at the higher levels; meanwhile, these rats showed more significant decreases in the count of CEPCs, the plasma level of VEGF etc., and their expression in myocardial tissue (P < 0.05 or P < 0.01). Our study showed that hyperlipidemia may attenuate the mobilization of BM EPCs induced by AMI via VEGF/eNOS/NO/MMP-9 signal pathway, which might partly account for hyperlipidemia hampering the repairs of AMI-induced cardiac injury.

Effectiveness Comparisons of Drug Therapy on Chronic Subdural Hematoma Recurrence: A Bayesian Network Meta-Analysis and Systematic Review

Objectives: We aim to compare the effectiveness of different drug treatments in improving recurrence in patients with chronic subdural hematoma (CSDH). Methods: Eligible randomized controlled trials (RCTs) and prospective trials were searched in PubMed, Cochrane Library, and Embase, from database inception to December 2021. After the available studies following inclusion and exclusion criteria were screened, the main outcome measures were strictly extracted. Taking the random-effects model, dichotomous data were determined and extracted by odds ratio (OR) with 95% credible interval (CrI), and a surface under the cumulative ranking curve (SUCRA) was generated to calculate the ranking probability of comparative effectiveness among each drug intervention. Moreover, we used the node-splitting model to evaluate inconsistency between direct and indirect comparisons of our network meta-analysis (NMA). Funnel plots were used to evaluate publication bias. Results: From the 318 articles found during initial citation screening, 11 RCTs and 3 prospective trials (n = 3,456 participants) were ultimately included in our study. Our NMA results illustrated that atorvastatin + dexamethasone (ATO+DXM) (OR = 0.06, 95% CrI 0.01, 0.89) was the most effective intervention to improve recurrence in patients with CSDH (SUCRA = 89.40%, 95% CrI 0.29, 1.00). Four drug interventions [ATO+DXM (OR = 0.06, 95% CrI 0.01, 0.89), DXM (OR = 0.18, 95% CrI 0.07, 0.41), tranexamic acid (TXA) (OR = 0.26, 95% CrI 0.07, 0.41), and ATO (OR = 0.41, 95% CrI 0.12, 0.90)] achieved statistical significance in improving recurrence in CSDH patients compared with the placebo (PLB) or standard neurosurgical treatment (SNT) group. Conclusion: Our NMA showed that ATO+DXM, DXM, ATO, and TXA had definite efficacy in improving recurrence in CSDH patients. Among them, ATO+DXM is the best intervention for improving recurrence in patients with CSDH in this particular population. Multicenter rigorous designed prospective randomized trials are still needed to evaluate the role of various drug interventions in improving neurological function or outcome. Systematic Review Registration: (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=299491), identifier (CRD 42022299491).

The Role of Endothelial Progenitor Cells in Atherosclerosis and Impact of Anti-Lipemic Treatments on Endothelial Repair

Cardiovascular complications are associated with advanced atherosclerosis. Although atherosclerosis is still regarded as an incurable disease, at least in its more advanced stages, the discovery of endothelial progenitor cells (EPCs), with their ability to replace old and injured cells and differentiate into healthy and functional mature endothelial cells, has shifted our view of atherosclerosis as an incurable disease, and merged traditional theories of atherosclerosis pathogenesis with evolving concepts of vascular biology. EPC alterations are involved in the pathogenesis of vascular abnormalities in atherosclerosis, but many questions remain unanswered. Many currently available drugs that impact cardiovascular morbidity and mortality have shown a positive effect on EPC biology. This review examines the role of endothelial progenitor cells in atherosclerosis development, and the impact standard antilipemic drugs, including statins, fibrates, and ezetimibe, as well as more novel treatments such as proprotein convertase subtilisin/kexin type 9 (PCSK9) modulating agents and angiopoietin-like proteins (Angtpl3) inhibitors have on EPC biology.

An updated systematic review and meta-analysis of the effect of statins on asymmetric dimethylarginine

OBJECTIVES

We conducted an updated systematic review and meta-analysis of the effect of statins on serum or plasma concentrations of the endogenous inhibitor of endothelial nitric oxide synthase, asymmetric N^G,N^G-dimethyl-l-arginine (ADMA).

METHODS

A systematic literature search was conducted in the electronic databases PubMed, Web of Science, and Scopus, from inception to July 2021. Risk of bias and certainty of evidence were assessed using the Joanna Briggs Institute Critical Appraisal Checklist for analytical studies and GRADE, respectively.

RESULTS

In 23 studies, reporting 25 treatment arms in 845 participants (mean age 53 years, 57% males, treatment duration 4-48 weeks), statins significantly reduced ADMA concentrations (SMD = -0.39, 95% CI -0.62 to -0.16, p = 0.001; moderate certainty of evidence). The extreme heterogeneity observed was substantially reduced in study subgroups of specific class and individual statins, regional areas, and analytical methods for ADMA concentrations. There was no publication bias. In sensitivity analysis, the corresponding SMD values were not substantially modified when individual studies were sequentially removed. Significant associations were observed, in meta-regression, between the SMD and publication year (t = -3.25, p = 0.003), but not baseline cholesterol concentrations.

CONCLUSION

Statin treatment significantly lowers ADMA concentrations. This effect is independent of baseline cholesterol. Prospective studies are required to determine whether ADMA-lowering mediates, at least partly, the protective effects of statins against atherosclerotic cardiovascular disease. (PROSPERO registration number: CRD42021275123).

Atorvastatin combined with dexamethasone in chronic subdural haematoma (ATOCH II): study protocol for a randomized controlled trial

BACKGROUND

Chronic subdural haematoma (CSDH) is a common condition in the elderly that often requires neurosurgical management. For small CSDH, evidence has emerged that statins may reduce haematoma volume and improve outcomes, presumably by reducing local inflammation and promoting vascular repair. We wish to extend this evidence in a study that aims to determine the efficacy and safety of atorvastatin combined with low-dose dexamethasone in patients with CSDH.

METHODS

The second ATorvastatin On Chronic subdural Hematoma (ATOCH-II) study is a multi-centre, randomized, placebo-controlled, double-blind trial which aims to enrol 240 adult patients with a conservative therapeutic indication for CSDH, randomly allocated to standard treatment with atorvastatin 20 mg combined with low-dose dexamethasone (or matching placebos) daily for 28 days, and with 152 days of follow-up. The primary outcome is a composite good outcome defined by any reduction from baseline in haematoma volume and survival free of surgery at 28 days. Secondary outcomes include functional outcome on the modified Rankin scale (mRS) and modified Barthel Index at 28 days, surgical transition and reduction in haematoma volumes at 14, 28 and 90 days.

DISCUSSION

This multi-centre clinical trial aims to provide high-quality evidence on the efficacy and safety of the combined treatment of atorvastatin and low-dose dexamethasone to reduce inflammation and enhance angiogenesis in CSDH.

TRIAL REGISTRATION

ChiCTR, ChiCTR1900021659 . Registered on 3 March 2019, http://www.chictr.org.cn/showproj.aspx?proj=36157 .

A comprehensive review on the lipid and pleiotropic effects of pitavastatin

The 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, or statins, are administered as first line therapy for hypercholesterolemia, both in primary and secondary prevention. There is a growing body of evidence showing that beyond their lipid-lowering effect, statins have a number of additional beneficial properties. Pitavastatin is a unique lipophilic statin with a strong effect on lowering plasma total cholesterol and triacylglycerol. It has been reported to have pleiotropic effects such as decreasing inflammation and oxidative stress, regulating angiogenesis and osteogenesis, improving endothelial function and arterial stiffness, and reducing tumor progression. Based on the available studies considering the risk of statin-associated muscle symptoms it seems to be also the safest statin. The unique lipid and non-lipid effects of pitavastatin make this molecule a particularly interesting option for the management of different human diseases. In this review, we first summarized the lipid effects of pitavastatin and then strive to unravel the diverse pleiotropic effects of this molecule.

Treatment of chronic subdural hematoma with atorvastatin combined with low-dose dexamethasone: phase II randomized proof-of-concept clinical trial

OBJECTIVE

The authors sought to test the hypothesis that adding dexamethasone (DXM) to atorvastatin (ATO) potentiates the effects of ATO on chronic subdural hematoma (CSDH).

METHODS

Sixty patients with CSDH underwent 5 weeks of treatment with an additional 7-week follow-up. Patients were randomized to receive a 5-week regimen of ATO 20 mg daily or ATO 20 mg daily plus a DXM regimen (ATO+DXM). The 5-week DXM regimen was 2.25 mg daily for 2 consecutive weeks, followed by 0.75 mg twice daily for 2 weeks and 0.75 mg once daily for 1 week. The primary endpoint was hematoma reduction assessed by neuroimaging at baseline and at 5 weeks of follow-up. Secondary outcomes included neurological improvement assessed by using the Markwalder's Grading Scale and Glasgow Coma Scale (MGS-GCS).

RESULTS

The mean patient age was 66.6 years, and 25% of patients were women. The patients who were treated with ATO+DXM had more obvious hematoma reduction at the 5th week (between-groups difference 18.37 ml; 95% CI 8.17-28.57; p = 0.0005). This reduction started from the 2nd week (14.51 ml; 95% CI 4.31-24.71; p = 0.0056) of treatment and persisted until the 12th week (17.50 ml; 95% CI 7.30-27.70; p = 0.0009). Complete recovery of neurological function (MGS-GCS grade 0) at 5 weeks was achieved in 83.33% and 32.14% of patients in the ATO+DXM and ATO groups, respectively. At the 5th week, patients receiving ATO+DXM had significantly lower levels of T cells and higher levels of regulatory T cells and endothelial progenitor cells in their peripheral blood.

CONCLUSIONS

ATO+DXM was more effective than ATO alone in reducing hematoma and improving neurological function in patients with CSDH. These results require further confirmation in a randomized placebo-controlled trial.Clinical trial registration no.: ChiCTR-IPR-14005573 (http://www.chictr.org.cn/index.aspx).

Intrinsic Vascular Repair by Endothelial Progenitor Cells in Acute Coronary Syndromes: an Update Overview

Bone marrow-derived endothelial progenitor cells (EPCs) play a key role in the maintenance of endothelial homeostasis and endothelial repair at areas of vascular damage. The quantification of EPCs in peripheral blood by flow cytometry is a strategy to assess this reparative capacity. The number of circulating EPCs is inversely correlated with the number of cardiovascular risk factors and to the occurrence of cardiovascular events. Therefore, monitoring EPCs levels may provide an accurate assessment of susceptibility to cardiovascular injury, greatly improving risk stratification of patients with high cardiovascular risk, such as those with an acute myocardial infarction. However, there are many issues in the field of EPC identification and quantification that remain unsolved. In fact, there have been conflicting protocols used to the phenotypic identification of EPCs and there is still no consensual immunophenotypical profile that corresponds exactly to EPCs. In this paper we aim to give an overview on EPCs-mediated vascular repair with special focus on acute coronary syndromes and to discuss the different phenotypic profiles that have been used to identify and quantify circulating EPCs in several clinical studies. Finally, we will synthesize evidence on the prognostic role of EPCs in patients with high cardiovascular risk.

Pitavastatin for lowering lipids

BACKGROUND

Pitavastatin is the newest statin on the market, and the dose-related magnitude of effect of pitavastatin on blood lipids is not known.

OBJECTIVES

Primary objective To quantify the effects of various doses of pitavastatin on the surrogate markers: LDL cholesterol, total cholesterol, HDL cholesterol and triglycerides in participants with and without cardiovascular disease. To compare the effect of pitavastatin on surrogate markers with other statins.  Secondary objectives To quantify the effect of various doses of pitavastatin on withdrawals due to adverse effects.  SEARCH METHODS: The Cochrane Hypertension Information Specialist searched the following databases for trials up to March 2019: the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 2, 2019), MEDLINE (from 1946), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We also contacted authors of relevant papers regarding further published and unpublished work. The searches had no language restrictions.

SELECTION CRITERIA

RCT and controlled before-and-after studies evaluating the dose response of different fixed doses of pitavastatin on blood lipids over a duration of three to 12 weeks in participants of any age with and without cardiovascular disease.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility criteria for studies to be included, and extracted data. We entered data from RCT and controlled before-and-after studies into Review Manager 5 as continuous and generic inverse variance data, respectively. Withdrawals due to adverse effects (WDAE) information was collected from the RCTs. We assessed all included trials using the Cochrane 'Risk of bias' tool under the categories of allocation (selection bias), blinding (performance bias and detection bias), incomplete outcome data (attrition bias), selective reporting (reporting bias), and other potential sources of bias.

MAIN RESULTS

Forty-seven studies (five RCTs and 42 before-and-after studies) evaluated the dose-related efficacy of pitavastatin in 5436 participants. The participants were of any age with and without cardiovascular disease, and pitavastatin effects were studied within a treatment period of three to 12 weeks. Log dose-response data over doses of 1 mg to 16 mg revealed strong linear dose-related effects on blood total cholesterol and LDL cholesterol and triglycerides. There was no dose-related effect of pitavastatin on blood HDL cholesterol, which was increased by 4% on average by pitavastatin. Pitavastatin 1 mg/day to 16 mg/day reduced LDL cholesterol by 33.3% to 54.7%, total cholesterol by 23.3% to 39.0% and triglycerides by 13.0% to 28.1%. For every two-fold dose increase, there was a 5.35% (95% CI 3.32 to 7.38) decrease in blood LDL cholesterol, a 3.93% (95% CI 2.35 to 5.50) decrease in blood total cholesterol and a 3.76% (95% CI 1.03 to 6.48) decrease in blood triglycerides. The certainty of evidence for these effects was judged to be high. When compared to other statins for its effect to reduce LDL cholesterol, pitavastatin is about 6-fold more potent than atorvastatin, 1.7-fold more potent than rosuvastatin, 77-fold more potent than fluvastatin and 3.3-fold less potent than cerivastatin. For the placebo group, there were no participants who withdrew due to an adverse effect per 109 subjects and for all doses of pitavastatin, there were three participants who withdrew due to an adverse effect per 262 subjects.

AUTHORS' CONCLUSIONS

Pitavastatin lowers blood total cholesterol, LDL cholesterol and triglyceride in a dose-dependent linear fashion. Based on the effect on LDL cholesterol, pitavastatin is about 6-fold more potent than atorvastatin, 1.7-fold more potent than rosuvastatin, 77-fold more potent than fluvastatin and 3.3-fold less potent than cerivastatin. There were not enough data to determine risk of withdrawal due to adverse effects due to pitavastatin.

Effect of negative-pressure wound therapy on the circulating number of peripheral endothelial progenitor cells in diabetic patients with mild to moderate degrees of ischaemic foot ulcer

Objective

To investigate the effect of negative-pressure wound therapy (NPWT) on the circulating number of endothelial progenitor cells (EPCs) in diabetic patients with mild to moderate degrees of ischemic foot ulcer.

Methods

We selected 84 diabetic patients who had a foot ulcer with a duration of at least four weeks and who had an ankle-brachial index of 0.5–0.9. Patients were assigned to one two groups according to 2:1 randomization: NPWT group ( n = 56) and non-NPWT (patients who did not receive NPWT) group ( n = 28). The control group (NC group) was composed of 18 patients who had normal glucose tolerance and lower extremity ulcer without arteriovenous disease. NPWT was performed on the ulcer after debridement for one week for patients in both the NPWT group and the NC group, and the patients in the non-NPWT group received conventional treatment process. The circulating number of EPCs was measured before and after various treatments, and the factors influencing their changes were analysed.

Results

After NPWT, the circulating number of EPCs significantly increased in both the NPWT group and the NC group ((85.3 ± 18.1) vs. (34.1 ± 12.5)/106 cells; (119.9 ± 14.4) vs. (66.1 ± 10.6)/106 cells, both P < 0.05). In contrast, the circulating number of EPCs had no significant change in the non-NPWT group ((45.2 ± 19.4) vs. (34.7 ± 16.8)/106 cells, P > 0.05). In addition, the circulating levels of vascular endothelial growth factor (VEGF) and the protein expressions of VEGF and stromal cell-derived factor-1α (SDF-1α) in the granulation tissue significantly increased after NPWT in both the NPWT and the NC group, but there was no significant change in the non-NPWT group. Compared with the non-NPWT group, the changes in VEGF and SDF-1α levels in the sera and granulation tissue were all significantly higher in both the NPWT and NC groups ( P < 0.05, P < 0.01, respectively). There was no significant difference in changes in the circulating number of EPCs in the peripheral blood and levels of VEGF and SDF-1α in the sera and granulation tissue between the NPWT and NC groups. Correlation analysis showed that the change in the circulating number of EPCs was correlated with the changes of VEGF and SDF-1α levels in the sera and granulation of the NPWT and NC groups ( P < 0.05).

Conclusion

NPWT may increase the circulating number of EPCs in diabetic patients with mild to moderate ischaemic foot ulcer as in non-diabetic controls, which may be attributed to the upregulation of systemic and local VEGF and SDF-1α levels.

Effect of statins on fasting glucose in non-diabetic individuals: nationwide population-based health examination in Korea

BACKGROUND

Increasing evidence suggest that statin therapy has a diabetogenic effect. Individual types of statin may have a different effect on glucose metabolism. Using the repeated nationwide population-based health screening data in Korea, we investigated the longitudinal changes in fasting glucose level of non-diabetic individuals by use of statins.

METHODS

From the National Health Screening Cohort, we included 379,865 non-diabetic individuals who had ≥ 2 health screening examinations with fasting blood glucose level measured in 2002-2013. Using the prescription records of statins in the database, we calculated the proportion of days covered (PDC) and average number of defined daily doses per day (anDDD) by statins. We constructed multivariate linear mixed models to evaluate the effects of statins on the changes in fasting glucose (Δglu).

RESULTS

High PDC by statins had a significant positive effect on Δglu (coefficient for PDC 0.093 mmol/L, standard error 0.007, p < 0.001). anDDD by statins was also positively associated with Δglu (coefficient for anDDD 0.119 mmol/L, standard error 0.009, p < 0.001). Unlike statins, the PDC by fibrate and ezetimibe were not significantly associated with Δglu. There was no significant interaction effect on Δglu between time interval and statin. Considering individual types of statins, use of atorvastatin, rosuvastatin, pitavastatin, and simvastatin were significantly associated with increase of Δglu. Pravastatin, lovastatin, and fluvastatin were also positively associated with Δglu, but were not statistically significant.

CONCLUSIONS

More adherent and intensive use of statins was significantly associated with an increase in fasting glucose of non-diabetic individuals. In subgroup analysis of individual statins, use of atorvastatin, rosuvastatin, pitavastatin and simvastatin had significant association with increase in fasting glucose. Pravastatin, lovastatin, and fluvastatin had non-significant trend toward an increased fasting glucose. Our findings suggest the medication class effect of statins inducing hyperglycemia.

Pitavastatin Upregulates Nitric Oxide Synthases in the Kidney of Spontaneously Hypertensive Rats and Wistar-Kyoto Rats

BACKGROUND

Clinical trials show potent renoprotective effects of pitavastatin (PTV), although the precise mechanism for these renoprotective effects is not fully clarified. The aim of this study was to examine the antihypertensive and renoprotective effects of PTV, focusing on the nitric oxide (NO) system.

METHODS

Male, 6-week-old, spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) were randomized to receive vehicle or PTV (2 mg/kg bodyweight) for 8 weeks. Blood pressure and urinary albumin excretion were measured every 2 weeks. After 8 weeks, plasma biochemical parameters and renal histology were examined. NO synthase isoform (neuronal, nNOS; inducible, iNOS; and endothelial, eNOS) expression and eNOS phosphorylation were examined by western blotting.

RESULTS

PTV attenuated hypertension and albuminuria development in SHR. PTV decreased glomerular desmin expression and medullary interstitial fibrosis in SHR. PTV tended to increase plasma NO in both strains but significantly increased urinary NO excretion only in WKY. PTV significantly increased nNOS and eNOS expression, enhanced eNOS phosphorylation at serine1177, and inhibited eNOS phosphorylation at threonine495 in the kidney of both strains.

CONCLUSIONS

PTV treatment led to increased renal NOS expression and upregulated eNOS activity in both SHR and WKY. The antihypertensive and renoprotective effects of PTV may be related to upregulation of the NO system.

Pitavastatin nanoparticle-engineered endothelial progenitor cells repair injured vessels

Endothelial progenitor cells (EPC) participate in vessel recovery and maintenance of normal endothelial function. Therefore, pitavastatin-nanoparticles (NPs)-engineered EPC may be effective in repairing injured vasculature. Pitavastatin-loaded poly(lactic-co-glycolic) acid (PLGA) NPs were obtained via ultrasonic emulsion solvent evaporation with PLGA as the carrier encapsulating pitavastatin. The effects and mechanism of pitavastatin-NPs on EPC proliferation in vitro were evaluated. Then, EPC that internalized pitavastatin-NPs were transplanted into rats after carotid artery injury. EPC homing, re-endothelialization, and neointima were evaluated by fluorescence labeling, evans Blue and hematoxylin/eosin (H&E) staining. Pitavastatin-NPs significantly improved EPC proliferation compared with control and pitavastatin group. Those effects were blocked by pretreatment with the pharmacological phosphoinositide 3-kinase (PI3K) blockers LY294002. After carotid artery injury, more transplanted EPC were detected in target zone in Pitavastatin-NPs group than pitavastatin and control group. Re-endothelialization was promoted and intimal hyperplasia was inhibited as well. Thus, pitavastatin-NPs promote EPC proliferation via PI3K signaling and accelerate recovery of injured carotid artery.

Active Stromal Cell-Derived Factor 1α and Endothelial Progenitor Cells are Equally Increased by Alogliptin in Good and Poor Diabetes Control

Background:

It is postulated that the ability of dipeptidyl peptidase-4 inhibitors (DPP-4-i) to increase circulating endothelial progenitor cells (EPCs) may be at least partly mediated by active stromal cell–derived factor 1α (SDF-1α) (a pivotal mediator of stem cell mobilization from the bone marrow). As other DPP-4-i were demonstrated to increase EPC concentrations, in this study, we sought to investigate the ability of the DPP-4-i alogliptin in modifying EPCs and SDF-1α, in patients with good and poor diabetes control.

Methods:

Two groups of diabetic patients on metformin were divided by hemoglobin A_1c (HbA_1c): Group A—those with HbA_1c ≤6.5% (28 patients) and Group B—those with HbA_1c 7.5% to 8.5% (31 patients). Both groups received alogliptin 25 mg/daily for 4 months. At baseline and 4 months later, clinical, laboratory parameters, EPCs, and active SDF-1α were determined.

Results:

After 4-month treatment with alogliptin, either Group A or Group B showed reduced HbA_1c levels and concomitant similar increase in EPCs and active SDF-1α.

Conclusions:

Alogliptin showed significant benefits in increasing EPCs and active SDF-1α either in good or poor diabetes control. The study demonstrated that similar to other DPP-4-i, also alogliptin is able to increase EPC concentrations, suggesting the existence of a class effect mediated by SDF-1α. The extent of increase in EPCs is independent from baseline diabetes control.

Vildagliptin, but not glibenclamide, increases circulating endothelial progenitor cell number: a 12-month randomized controlled trial in patients with type 2 diabetes

Background

Fewer circulating endothelial progenitor cells (EPCs) and increased plasma (C-term) stromal cell-derived factor 1α (SDF-1α), a substrate of DPP-4, are biomarkers, and perhaps mediators, of cardiovascular risk and mortality. Short-term/acute treatment with DPP-4 inhibitors improve EPC bioavailability; however, long-term effects of DPP-4i on EPCs bioavailability/plasma (C-term) SDF-1α are unknown.

Methods

Randomized (2:1) open-label trial to compare the effects of vildagliptin (V) (100 mg/day) vs glibenclamide (G) (2.5 mg bid to a maximal dose of 5 mg bid) on circulating EPC levels at 4 and 12 months of treatment in 64 patients with type 2 diabetes in metformin failure. At baseline, and after 4 and 12 months, main clinical/biohumoral parameters, inflammatory biomarkers, concomitant therapies, EPC number (CD34⁺/CD133⁺/KDR⁺/10⁶ cytometric events) and plasma (C-term) SDF-1α (R&D system) were assessed.

Results

Baseline characteristics were comparable in the two groups. V and G similarly and significantly (p < 0.0001) improved glucose control. At 12 months, V significantly increased EPC number (p < 0.05) and significantly reduced (C-term) SDF-1α plasma levels (p < 0.01) compared to G, with no differences in inflammatory biomarkers.

Conclusions

V exerts a long-term favorable effect on EPC and (C-term) SDF-1α levels at glucose equipoise, thereby implying a putative beneficial effect on vascular integrity.

Trial registration Clinical Trials number: NCT01822548; name: Effect of Vildagliptin vs. Glibenclamide on Circulating Endothelial Progenitor Cell Number Type 2 Diabetes. Registered 28 March, 2013

Endothelial progenitor cells: Exploring the pleiotropic effects of statins

Statins have become a cornerstone of risk modification for ischaemic heart disease patients. A number of studies have shown that they are effective and safe. However studies have observed an early benefit in terms of a reduction in recurrent infarct and or death after a myocardial infarction, prior to any significant change in lipid profile. Therefore, pleiotropic mechanisms, other than lowering lipid profile alone, must account for this effect. One such proposed pleiotropic mechanism is the ability of statins to augment both number and function of endothelial progenitor cells. The ability to augment repair and maintenance of a functioning endothelium may have profound beneficial effect on vascular repair and potentially a positive impact on clinical outcomes in patients with cardiovascular disease. The following literature review will discuss issues surrounding endothelial progenitor cell (EPC) identification, role in vascular repair, factors affecting EPC numbers, the role of statins in current medical practice and their effects on EPC number.

Modulating putative endothelial progenitor cells for the treatment of endothelial dysfunction and cardiovascular complications in diabetes

Diabetes induces a decrease in the number and function of different pro-angiogenic cell types generically designated as putative endothelial progenitor cells (EPC), which encompasses cells from myeloid origin that act in a paracrine fashion to promote angiogenesis and putative "true" EPC that contribute to endothelial replacement. This not only compromises neovasculogenesis in ischemic tissues but also impairs, at an early stage, the reendotheliziation process at sites of injury, contributing to the development of endothelial dysfunction and cardiovascular complications. Hyperglycemia, insulin resistance and dyslipidemia promote putative EPC dysregulation by affecting the SDF-1/CXCR-4 and NO pathways and the p53/SIRT1/p66Shc axis that contribute to their mobilization, migration, homing and vasculogenic properties. To optimize the clinical management of patients with hypoglycemic agents, statins and renin-angiotensin system inhibitors, which display pleiotropic effects on putative EPC, is a first step to improve their number and angiogenic potential but specific strategies are needed. Among them, mobilizing therapies based on G-CSF, erythropoietin or CXCR-4 antagonism have been developed to increase putative EPC number to treat ischemic diseases with or without prior cell isolation and transplantation. Growth factors, genetic and pharmacological strategies are also evaluated to improve ex vivo cultured EPC function before transplantation. Moreover, pharmacological agents increasing in vivo the bioavailability of NO and other endothelial factors demonstrated beneficial effects on neovascularization in diabetic ischemic models but their effects on endothelial dysfunction remain poorly evaluated. More experiments are warranted to develop orally available drugs and specific agents targeting p66Shc to reverse putative EPC dysfunction in the expected goal of preventing endothelial dysfunction and diabetic cardiovascular complications.

Does statin therapy reduce plasma VEGF levels in humans? A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The effect of statins on plasma concentrations of vascular endothelial growth factor (VEGF), the main angiogenic growth factor with pro-inflammatory and atherogenic properties, is controversial. A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to obtain a conclusive result in humans.

METHODS

PubMed-Medline, SCOPUS, Web of Science and Google Scholar databases were searched to identify RCTs investigating the impact of statins on plasma VEGF concentrations. A random-effects model and the generic inverse variance method were used for quantitative data synthesis. Meta-regression, sensitivity analysis and publication bias assessments were performed using standard methods.

RESULTS

Eight RCTs examining the effects of statins on plasma VEGF concentrations were included. Meta-analysis suggested a significant reduction of plasma VEGF levels following statin therapy (weighed mean difference: -19.88 pg/mL, 95% CI: -35.87, -3.89, p=0.015). VEGF reductions were observed in the subsets of trials with treatment durations ≥4 weeks (-19.54, -37.78, -1.30, p=0.036), LDL-C reductions ≥50 mg/dL (-28.59, -43.68, -13.50, p<0.001), lipophilic statins (-22.31, -40.65, -3.98, p=0.017), and diseased populations (-21.08, -39.97, -2.18, p=0.029), but not in the opposite subsets. Meta-regression also suggested a significant association between changes in plasma VEGF levels and LDL-C changes, treatment duration, but not molar dose of statins.

CONCLUSIONS

These results suggest a significant reduction in plasma VEGF concentrations following statin therapy. This effect depends on duration of treatment, LDL-lowering activity, lipophilicity of statins, and health status of studied individuals. Further RCTs are needed to explore if the VEGF reduction is implicated in the statin benefits on cardiovascular outcomes.