Cilostazol inhibits high glucose- and angiotensin II-induced type 1 plasminogen activator inhibitor expression in artery wall and neointimal region after vascular injury

Comparative effects of lipid lowering, hypoglycemic, antihypertensive and antiplatelet medications on carotid artery intima-media thickness progression: a network meta-analysis

Background

Carotid artery intima-media thickness (cIMT) progression is a surrogate marker of atherosclerosis with a high predictive value for future CVD risk. This study evaluates the comparative efficacies of lipid lowering, hypoglycemic, antihypertensive and antiplatelet medications on cIMT progression.

Methods

We conducted a network meta-analysis (NMA) to evaluate the relative efficacies of several drug classes in modifying cIMT progression. After a literature search in several electronic databases, studies were selected by following predetermined eligibility criteria. An inverse variance-heterogeneity model was used for NMA. Sensitivity analyses were performed to check the reliability of the overall NMA, and transitivity analyses were performed to examine the effects of modifiers on the NMA outcomes.

Results

Data were taken from 47 studies (15,721 patients; age: 60.2 years [95% confidence interval (CI) 58.8, 61.6]; BMI: 27.2 kg/m² [95% CI 26.4, 28.0]; and gender: 58.3% males [95% CI 48.3, 68.3]). Treatment duration was 25.8 months [95% CI 22.9, 28.7]. Of the 13 drug classes in the network, treatment with phosphodiesterase III inhibitors was the most effective in retarding annual mean cIMT against network placebo (weighted mean difference (WMD) − 0.059 mm [95% CI − 0.099, − 0.020) followed by the calcium channel blockers (WMD − 0.055 mm [95% CI − 0.099, 0.001]) and platelet adenosine diphosphate inhibitors (WMD − 0.033 mm [95% CI − 0.058, 0.008]). These 3 drug classes also attained the same positions when the NMA was conducted by using first-year changes in mean cIMT. In transitivity analyses, longer treatment duration, higher body mass index (BMI), and a higher baseline cIMT were found to be independently associated with a lesser reduction in annual mean cIMT. However, in a multivariate analysis with these 3 modifiers, none of these factors was significantly associated with annual change in mean cIMT. In the placebo group, age was inversely associated with annual change in mean cIMT independently.

Conclusion

Phosphodiesterase III inhibitors and calcium channel blockers are found more effective than other drug classes in retarding cIMT progression. Age, BMI, and baseline cIMT may have some impact on these outcomes.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0817-1) contains supplementary material, which is available to authorized users.

Daily melatonin protects the endothelial lineage and functional integrity against the aging process, oxidative stress, and toxic environment and restores blood flow in critical limb ischemia area in mice

We tested the hypothesis that daily melatonin treatment protects endothelial lineage and functional integrity against the aging process, oxidative stress/endothelial denudation (ED), and toxic environment and restored blood flow in murine critical limb ischemia (CLI). In vitro study using HUVECs, in vivo models (ie, CLI through left femoral artery ligation and ED through carotid artery wire injury), and model of lipopolysaccharide-induced aortic injury in young (3 months old) and aged (8 months old) mice were used to elucidate effects of melatonin treatment on vascular endothelial integrity. In vitro study showed that menadione-induced oxidative stress (NOX-1/NOX-2), inflammation (TNF-α/NF-kB), apoptosis (cleaved caspase-3/PARP), and mitochondrial damage (cytosolic cytochrome c) in HUVECs were suppressed by melatonin but reversed by SIRT3-siRNA (all P < .001). In vivo, reduced numbers of circulating endothelial progenitor cells (EPCs) (C-kit/CD31+/Sca-1/KDR+/CXCR4/CD34+), and angiogenesis (Matrigel assay of bone marrow-derived EPC and ex vivo aortic ring cultures) in older (compared with younger) mice were significantly reversed through daily melatonin administration (20 mg/kg/d, ip) (all P < .001). Aortic vasorelaxation and nitric oxide release were impaired in older mice and reversed in age-match mice receiving melatonin (all P < .01). ED-induced intimal/medial hyperplasia, reduced blood flow to ischemic limb, and angiogenesis (reduced CD31+/vWF+ cells/small vessel number) were improved after daily melatonin treatment (all P < .0001). Lipopolysaccharide-induced aortic endothelial cell detachment, which was more severe in aged mice, was also alleviated after daily melatonin treatment (P < .0001). Daily melatonin treatment protected both structural and functional integrity of vascular endothelium against aging-, oxidative stress-, lipopolysaccharide-, and ischemia-induced damage probably through upregulating the SIRT signaling pathway.

Effect of cilostazol on neointimal hyperplasia in iliac arteries of pigs after transluminal angioplasty

OBJECTIVE

to evaluate whether systemic administration of cilostazol reduces neointimal hyperplasia in iliac arteries of pigs submitted to balloon catheter angioplasty.

METHODS

twenty pigs underwent angioplasty with a 6x40 mm balloon catheter in the right common iliac artery, guided by Doppler ultrasound. The animals were randomized into two groups: group 1 (n=10), which received 50mg cilostazol twice a day, and group 2 (n=10), control. After 30 days, the animals were killed and the iliac arteries prepared for histological analysis. The histological sections were digitized and analyzed by digital morphometry. Statistical analysis was performed using the Student t and Mann-Whitney tests.

RESULTS

when comparing the iliac arteries submitted to angioplasty with those not subjected to angioplasty, there was significant neointimal hyperplasia (0.228 versus 0.119 mm2; p=0.0001). In arteries undergoing angioplasty, there was no difference between group 1 (cilostazol) and group 2 (control) as for the lumen area (2.277 versus 2.575 mm2; p=0.08), the tunica intima (0.219 versus 0.237 mm2; p=0.64), the tunica media (2.262 vs. 2.393 mm2; p=0.53) and the neointimal occlusion percentage (8.857 vs. 9.257 %; p=0.82).

CONCLUSION

the use of cilostazol 50mg administered in two daily doses did not reduce neointimal hyperplasia in iliac arteries of pigs submitted to balloon angioplasty catheter.

Continuous daily use of cilostazol prevents in-stent restenosis following carotid artery stenting: serial angiographic investigation of 229 lesions

BACKGROUND

Several studies have reported that cilostazol (CLS) may reduce in-stent restenosis (ISR) after carotid artery stenting (CAS). However, it is not known for how long CLS must be continued to prevent ISR.

METHODS

We retrospectively reviewed a prospectively collected database of patients who underwent elective CAS and follow-up angiography at 3 months and 1 year after the procedure. ISR was defined as stenosis of 50% or greater on digital subtraction angiography. The cumulative incidence rates of angiographic ISR were compared between the three groups, divided according to duration of CLS use : (1) patients who were maintained on CLS for 12 months or more after CAS (12M CLS group, n=70), (2) patients who were treated with CLS for the first 3 months after CAS (3M CLS group, n=23), and (3) patients who did not receive CLS (no CLS group, n=136).

RESULTS

A total of 229 lesions in 199 patients were included in our analysis. During a median follow-up of 365 days, ISR was detected in 15 lesions. The cumulative ISR rates overall and in the 12M CLS, 3M CLS, and no CLS groups were 5.6%, 0%, 5.0%, and 8.4%, respectively, at 1 year, and the log rank test showed that there was a significant difference between the three groups (p<0.05). Cox regression analysis demonstrated that the 12M CLS group had a significantly lower risk of ISR than the 3M CLS group (adjusted relative risk (aRR) 3.06e-10, 95% CI 0 to 0.51, p<0.05) and the no CLS group (aRR 1.41e-10, 95% CI 0 to 0.15, p<0.001), whereas no difference was found between the 3M CLS group and the no CLS group.

CONCLUSIONS

An overall cumulative ISR rate of 5.6% was documented angiographically at 1 year after CAS. Continuous daily use of CLS (for at least 1 year) may have a beneficial effect on long term prevention of ISR.

Statins suppress glucose-induced plasminogen activator inhibitor-1 expression by regulating RhoA and nuclear factor-κB activities in cardiac microvascular endothelial cells

The aim of this study was to investigate the possible proinflammatory signaling pathways involved in statin inhibition of glucose-induced plasminogen activator inhibitor-1 (PAI-1) expression in cardiac microvascular endothelial cells (CMECs). Primary rat CMECs were grown in the presence of 5.7 or 23 mmol/L glucose. PAI-1 mRNA and protein expression levels were measured by realtime polymerase chain reaction, Western blotting and enzyme-linked immunosorbent assay, respectively. A pull-down assay was performed to determine RhoA activity. IκBα protein expression was measured by Western blotting, nuclear factor (NF)-κB activation was detected by electrophoretic mobility shift assay and its transcription activity was determined by a dual luciferase reporter gene assay. PAI-1 mRNA and protein expression levels were both increased with high glucose concentrations, but they were significantly suppressed by simvastatin and atorvastatin treatment (P < 0.01) and the effects were reversed by mevalonate (100 μmol/L) and geranylgeranyl pyrophosphate (10 μmol/L) but not farnesyl pyrophosphate (10 μmol/L). Such effects were similar to those of a RhoA inhibitor, C3 exoenzyme (5 μg/mL), inhibitors of RhoA kinase (ROCK), Y-27632 (10 μmol/L) and hydroxyfasudil (10 μmol/L) and an NF-κB inhibitor, BAY 11-7082 (5 μmol/L). High glucose-induced RhoA and NF-κB activations in CMECs were both significantly inhibited by statins (P < 0.01). Simvastatin and atorvastatin equally suppress high glucose-induced PAI-1 expression. These effects of statins may occur partly by regulating the RhoA/ROCK-NF-κB pathway. The multifunctional roles of statins may be particularly beneficial for patients with metabolic syndrome.

Glibenclamide induces collagen IV catabolism in high glucose-stimulated mesangial cells

We have shown the full prevention of mesangial expansion in insulin-deficient diabetic rats by treatment with clinically-relevant dosages of glibenclamide (Glib). Studies in mesangial cells (MCs) also demonstrated reduction in the high glucose (HG)-induced accumulation of collagens, proposing that this was due to increased catabolism. In the present study, we investigated the signaling pathways that may be implicated in Glib action. Rat primary MCs were exposed to HG for 8 weeks with or without Glib in therapeutic (0.01 μM) or supratherapeutic (1.0 μM) concentrations. We found that HG increased collagen IV protein accumulation and PAI-1 mRNA and protein expression, in association with decreased cAMP generating capacity and decreased PKA activity. Low Glib increased collagen IV mRNA but fully prevented collagen IV protein accumulation and PAI-1 overexpression while enhancing cAMP formation and PKA activity. MMP2 mRNA, protein expression and gelatinolytic activity were also enhanced. High Glib was, overall, ineffective. In conclusion, low dosage/concentration Glib prevents HG-induced collagen accumulation in MC by enhancing collagen catabolism in a cAMP-PKA-mediated PAI-1 inhibition.

Effect of cilostazol on the progression of carotid intima-media thickness: a meta-analysis of randomized controlled trials

BACKGROUND

It has been well established that cilostazol has anti-proliferative effect against in-stent restenosis. However, it remains unclear whether cilostazol can prevent the progression of carotid atherosclerosis.

METHODS AND RESULTS

We performed a meta-analysis of all relevant randomized controlled trials (RCTs) to evaluate the effect of cilostazol on the progression of carotid intima-media thickness (IMT). Five RCTs with 698 patients [597 subjects with type 2 diabetes mellitus (T2DM)] were included in this study. Cilostazol was associated with a significant reduction in the progression of carotid IMT (WMD, -0.08mm, 95% CI -0.13, -0.04; P=0.00003). Subgroup analysis shows that cilostazol monotherapy or addition to dual antiplatelet therapy (aspirin and clopidogrel) was superior to placebo (WMD, -0.04mm, 95% CI -0.05, -0.03; P<0.00001), no antiplatelet medication (WMD, -0.12mm, 95% CI -0.21, -0.03; P=0.008), aspirin monotherapy (WMD, -0.06mm, 95% CI -0.12, 0.00; P=0.04) or dual antiplatelet therapy (WMD, -0.16mm, 95% CI -0.30, -0.02; P=0.03) in preventing the progression of carotid IMT. Cilostazol resulted in a significant decrease in total cholesterol (WMD -8.47mg/dl, 95% CI -14.18, -2.75; P=0.004) and LDL-C (WMD -8.25mg/dl, 95% CI -14.15, -2.36; P=0.006) and favorable trends in reducing triglyceride (WMD -15.83mg/dl, 95% CI -32.14, 0.48; P=0.06).

CONCLUSION

It suggests that cilostazol may have beneficial effects in preventing the progression of carotid atherosclerosis and improving pro-atherogenic lipid profile, especially in patients with T2DM. Whether the anti-atherosclerotic effect of cilostazol is independent of improving pro-atherogenic dyslipidemia is worth further investigation.

Posttranscriptional regulation of expression of plasminogen activator inhibitor type-1 by cAMP in HepG2 liver cells

Altered expression of plasminogen activator inhibitor type-1 (PAI-1), a physiologic fibrinolysis inhibitor, is implicated in atherosclerosis. Cyclic adenosine monophosphate (cAMP) alters PAI-1 expression in several cells. Nevertheless, posttranscriptional regulation of PAI-1 has not been elucidated. To determine whether cAMP affects PAI-1 expression at posttranscriptional level, we determined promoter activity, mRNA levels, 3'-untranslated region (UTR) activity and protein levels of PAI-1 using HepG2 cells. cAMP decreased PAI-1 promoter activity at 24 h and mRNA expression at 4 h while it increased mRNA expression and accumulation of PAI-1 protein into media at 24 h. Human PAI-1 mRNA exists in two subspecies (3.2 and 2.2 kb), and cAMP increased baseline luciferase activity of 3'-UTR of the 3.2 kb PAI-1 mRNA [3'-UTR (+1358-3176)] and 1 kb fragment of 3'-terminus of 3'-UTR of 3.2 kb mRNA [3'-UTR (+2177-3176)]. cAMP increased PAI-1 protein expression despite decrease in promoter activity, presumably by regulating PAI-1 expression at the posttranscriptional level and thereby affecting mRNA stability. The 53-nt fragment in 3'-UTR (+2591 to +2643 nt) was involved in posttranscriptional regulation by cAMP. Thus, cAMP can stabilize 3.2 kb PAI-1 mRNA mediated by specific effects on 3'-UTR, and these effects are associated with increased expression of PAI-1 protein.

Modulation of TGF-β/BMP-6 expression and increased levels of circulating smooth muscle progenitor cells in a type I diabetes mouse model

Background

Diabetic patients experience exaggerated intimal hyperplasia after endovascular procedures. Recently it has been shown that circulating smooth muscle progenitor cells (SPC) contribute to intimal hyperplasia. We hypothesized that SPC differentiation would be increased in diabetes and focused on modulation of TGF-β/BMP-6 signaling as potential underlying mechanism.

Methods

We isolated SPC from C57Bl/6 mice with streptozotocin-induced diabetes and controls. SPC differentiation was evaluated by immunofluorescent staining for αSMA and collagen Type I. SPC mRNA expression of TGF-β and BMP-6 was quantified using real-time PCR. Intima formation was assessed in cuffed femoral arteries. Homing of bone marrow derived cells to cuffed arterial segments was evaluated in animals transplanted with bone marrow from GFP-transgenic mice.

Results

We observed that SPC differentiation was accelerated and numeric outgrowth increased in diabetic animals (24.6 ± 8.8 vs 8.3 ± 1.9 per HPF after 10 days, p < 0.05). Quantitative real-time PCR showed increased expression of TGF-β and decreased expression of the BMP-6 in diabetic SPC. SPC were MAC-3 positive, indicative of monocytic lineage. Intima formation in cuffed arterial segments was increased in diabetic mice (intima/media ratio 0.68 ± 0.15 vs 0.29 ± 0.06, p < 0.05). In GFP-chimeric mice, bone marrow derived cells were observed in the neointima (4.4 ± 3.3 cells per section) and particularly in the adventitia (43.6 ± 9.3 cells per section). GFP-positive cells were in part MAC-3 positive, but rarely expressed α-SMA.

Conclusions

In conclusion, in a diabetic mouse model, SPC levels are increased and SPC TGF-β/BMP-6 expression is modulated. Altered TGF-β/BMP-6 expression is known to regulate smooth muscle cell differentiation and may facilitate SPC differentiation. This may contribute to exaggerated intimal hyperplasia in diabetes as bone marrow derived cells home to sites of neointima formation.