Human urine kininogenase attenuates balloon-induced intimal hyperplasia in rabbit carotid artery through transforming growth factor ß1/Smad2/3 signaling pathway.

OBJECTIVE: Effective treatments against restenosis after percutaneous transluminal angioplasty and stenting are largely lacking. Human tissue kallikrein gene transfer has been shown to be able to attenuate neointima formation induced by balloon catheter. As a tissue kallikrein in vivo, human urinary kininogenase (HUK) is widely used to prevent ischemia-reperfusion injury. However, the effects of HUK on neointima formation have not been explored. We therefore investigated whether HUK could alleviate balloon catheter-induced intimal hyperplasia in rabbits fed with high-fat diets. METHODS: The effects of HUK on neointima and atherosclerosis formation were analyzed by hematoxylin-eosin staining and immunohistochemical staining in balloon-injured carotid arteries of rabbits. Local inflammatory response was evaluated by detecting the gene expression of tumor necrosis factor α and interleukin 1ß with real-time quantitative polymerase chain reaction plus the invasion of macrophages with immunohistochemical staining. Western blotting was employed to investigate the effects of HUK on activities of endothelial nitric oxide synthase (eNOS), transforming growth factor ß1 (TGF-ß1), and Smad signaling pathway. The long-term effect of HUK on intimal hyperplasia of the injured carotid artery was assessed by angiography. RESULTS: Quantitative image analysis showed that intravenous administration of HUK for 14 days significantly decreased the intimal areas and intima area/media area ratios (day 14, 54% decrease in intimal area and 58% decrease in intima area/media area ratios; day 28, 63% and 85%). Significant decreases were also noted in macrophage foam cell-positive area after 7-day or 14-day administration of HUK (day 7, 69% decrease in intimal area and 78% decrease in media area; day 14, 79% and 60%; day 28, 68% and 44%). Actin staining for smooth muscle cells in neointima at 2 months showed similar results (vascular smooth muscle cell-positive area of neointima, 28.21% ± 5.58% vs 43.78% ± 8.36%; P < .05). Real-time quantitative polymerase chain reaction or Western blot analysis showed that HUK reduced expression of tumor necrosis factor α, interleukin 1ß, TGF-ß1, and p-Smad2/3 but increased the expression of p-eNOS. Angiography analysis showed that 14-day administration of HUK significantly decreased the degree of stenosis (26.8% ± 7.1% vs 47.9% ± 5.7%; P < .01) at 2 months after balloon injury. CONCLUSIONS: Our results indicate that HUK is able to attenuate atherosclerosis formation and to inhibit intimal hyperplasia by downregulating TGF-ß1 expression and Smad2/3 phosphorylation, upregulating eNOS activity. HUK may be a potential therapeutic agent to prevent stenosis after vascular injury.

Association of heme oxygenase-1 gene rs2071746 polymorphism with vascular outcomes in patients with atherosclerotic stroke.

As an inducible isoform of heme oxygenase (HO), HO-1 was suggested to have an anti-oxidative stress, anti-inflammatory, anti-apoptotic and anti-proliferative effect. It was regarded as an important cytoprotective enzyme. We undertook this study to investigate whether HO-1 gene rs2071746 polymorphism was associated with clinical outcomes in atherosclerosis ischemic stroke patients. Between December 2009 and October 2012, consecutive atherosclerosis ischemic stroke patients were enrolled. The primary endpoint was the composite of vascular death, nonfatal ischemic stroke and myocardial infarct. A total of 961 patients were enrolled. After an average follow-up of 15.13 (SD=7.42) months, 89 patients (9.26%) had the primary endpoint. The cumulative incidence of the primary endpoint was significantly lower in A carriers (AT+AA) than TT genotype (7.9% vs. 12.2%, HR=0.648, 95% CI: 0.425-0.988, P=0.044). After adjustment for age, sex and other cardiovascular risk factors, we found that A carrier was an independent protective factor for atherosclerosis ischemic stroke (HR=0.646, 95% CI: 0.420-0.994, P=0.047). Age (HR=1.023, P=0.028) and low level of HDL (HR=1.772, P=0.012) were independent risk factors for the primary endpoint. In conclusion, HO-1 gene rs2071746 A allele carrier might be a protective factor for patients with atherosclerotic stroke.

Tissue kallikrein preventing the restenosis after stenting of symptomatic MCA atherosclerotic stenosis (KPRASS).

RATIONALE: Many recent studies suggest that the kallikrein-kinin system play a protective role in the impairment of vascular smooth muscle cells and vascular endothelial cell. AIMS: The study aims to determine whether tissue kallikrein is efficacy for preventing the long-term in-stent restenosis after stenting of symptomatic atherosclerotic stenosis of the middle cerebral artery M1 segment. DESIGN: This is a Phase II, randomized, single-blinded, controlled trial. In line with SAMMPRIS stenting indications, patients (n = 90) with the symptomatic the middle cerebral artery M1 segment stenosis ≥ 70% and successfully treated with stent will be enrolled. Eligible patients will be randomized using computer generated numbers, and allocated to receive tissue kallikrein treatment or not. Patients in tissue kallikrein treatment group will be prescribed with intravenous infusion of tissue kallikrein (0.15 PNAU/d, dissolved in 100 ml saline) for 7 days after stenting and then oral administration of pancreatic kallikrein enteric-coated tablet (240 U, 3/d) to the end of study. As the foundation treatment, all the enrolled patients will receive aspirin (100 mg/d), clopidogrel (75 mg/d), and atorvastatin (20 mg/d) for the first 6 months and continue with the combination of aspirin and atorvastatin at the previous dosage. STUDY OUTCOMES: Patients will be evaluated at 1, 6 and 12 months after stenting. The primary outcomes are the in-stent restenosis rate, new stroke or aggravation of the previous ischemic stroke ipsilateral to the severe stenotic artery. Secondary outcomes include stroke of other artery territories, myocardial infarction and vascular death. Modification of stroke knowledge, exercise and diet habit, smoking cessation and available laboratory data will also be recorded. CONCLUSION: As our pilot study, tissue kallikrein would be expected to prevent the long-term in-stent restenosis after stenting of the symptomatic middle cerebral artery dramatically.