Koronare Restenose

Nanomedicine for Diagnosis and Treatment of Atherosclerosis

With the changing disease spectrum, atherosclerosis has become increasingly prevalent worldwide and the associated diseases have emerged as the leading cause of death. Due to their fascinating physical, chemical, and biological characteristics, nanomaterials are regarded as a promising tool to tackle enormous challenges in medicine. The emerging discipline of nanomedicine has filled a huge application gap in the atherosclerotic field, ushering a new generation of diagnosis and treatment strategies. Herein, based on the essential pathogenic contributors of atherogenesis, as well as the distinct composition/structural characteristics, synthesis strategies, and surface design of nanoplatforms, the three major application branches (nanodiagnosis, nanotherapy, and nanotheranostic) of nanomedicine in atherosclerosis are elaborated. Then, state-of-art studies containing a sequence of representative and significant achievements are summarized in detail with an emphasis on the intrinsic interaction/relationship between nanomedicines and atherosclerosis. Particularly, attention is paid to the biosafety of nanomedicines, which aims to pave the way for future clinical translation of this burgeoning field. Finally, this comprehensive review is concluded by proposing unresolved key scientific issues and sharing the vision and expectation for the future, fully elucidating the closed loop from atherogenesis to the application paradigm of nanomedicines for advancing the early achievement of clinical applications.

Association of the DNA Methyltransferase and Folate Cycle Enzymes’ Gene Polymorphisms with Coronary Restenosis

Background: In recent years, the interest in genetic predisposition studies for coronary artery disease and restenosis has increased. Studies show that polymorphisms of genes encoding folate cycle and homocysteine metabolism enzymes significantly contribute to atherogenesis and endothelial dysfunction. The purpose of this study was to examine some SNPs of genes coding for folate cycle enzymes and DNA methyltransferases as risk factors for in-stent restenosis. Methods: The study included 113 patients after stent implantation and 62 patients without signs of coronary artery disease at coronary angiography as the control group. Real-time PCR and RFLP-PCR were applied to genotype all participants for MTHFR rs1801133, MTHFR rs1801131, MTR rs1805087, MTRR rs1801394, DNMT1 rs8101626, DNMT3B rs1569686, and DNMT3B rs2424913 gene polymorphisms. Statistical data processing was carried out using the R language and the SPSS Statistics 20 software. Results: Statistically significant differences in the DNMT3B gene polymorphisms were found between patients with and without in-stent restenosis. An association of TT rs1569686 and TT rs2424913 genotypes with the development of restenosis was revealed. The TT rs1569686 genotype was more frequent in the patients under the age of 65 years and in the subgroup of patients with post-12-month restenosis, as was the minor GG genotype for MTR rs1805087. The homozygous TT genotype for MTHFR rs1801133 was significantly more frequent in the subgroup over 65 years old. The frequencies of the heterozygous genotype for the MTRR gene and the minor GG homozygotes for the DNMT1 gene were significantly higher in the subgroup with in-stent restenosis under 65 years old. Conclusions: The results of this study could be used for a comprehensive risk assessment of ISR development, determining the optimal tactics and an individual approach in the treatment of patients with coronary artery disease before or after percutaneous coronary interventions, including homocysteine-lowering treatment in patients with hyperhomocysteinemia and a high risk of in-stent restenosis.

Risk factors of in-stent restenosis in patients with diabetes mellitus after percutaneous coronary intervention: A protocol for systematic review and meta-analysis

BACKGROUND

Percutaneous coronary intervention (PCI) has become one of the effective methods for the treatment of coronary heart disease (CHD). However, it is easy to have in-stent restenosis (ISR), even cardiovascular events after PCI, which affects the therapeutic effects. The incidence of ISR in diabetes mellitus (DM) patients increased by 2 to 4 times. Early identification of the risk factors of ISR in DM patients after PCI may help clinical staff to prevent and intervene as soon as possible, so it is very important to improve the clinical outcomes of DM patients. Although scholars at home and abroad have studied and summarized the risk factors of ISR in DM patients after PCI, the conclusions are different. Therefore, in this study, meta-analysis was used to summarize the risk factors of ISR in DM patients after PCI, and to explore the characteristics of high-risk groups of ISR, thus providing reference for early identification and prevention of ISR.

METHODS

We will search related literature from PubMed, Embase, Cochrane Library, Web of Science, China Biology Medicine Database, China National Knowledge Infrastructure, China Science and Technology Journal Database, and Wanfang Database. Eligible studies will be screened based on inclusion criteria. Meanwhile, data extraction, risk of bias assessment, publication bias assessment, subgroup analysis, and quality assessment will be performed. Review Manager Version 5.3 software will be applied for data analysis. Each process is independently conducted by 2 researchers. If there is any objection, it will be submitted to a third researcher for resolution.

RESULTS

We will disseminate the findings of this systematic review and meta-analysis via publications in peer-reviewed journals.

CONCLUSIONS

The results of this analysis can be used to generate a risk prediction model and provide an intervention strategy for the occurrence of ISR in DM patients after PCI.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/WC87Y.

[Clinical implications of the fourth universal definition of myocardial infarction]

This disease with its multiple ischemic and non-ischemic manifestations is classified based on the fourth universal definition of myocardial infarction (MI). An acute myocardial injury is defined as a significant increase of cardiac troponins (cTn). In patients with an additional myocardial ischemia, which is defined by certain clinical, electrocardiographic, imaging and angiographic criteria, the diagnosis of acute MI can be made. Etiologically, MI can be divided into 5 types: type 1 ischemic by plaque rupture or plaque erosion with thrombus formation, type 2 imbalance between myocardial oxygen demand and supply, type 3 MI as suspected cause of death before determination of cTn, type 4a <48 h after percutaneous coronary intervention (PCI), type 4b stent thrombosis, type 4c in-stent stenosis and type 5 <48 h after coronary artery bypass grafting (CABG). This classification reflects the heterogeneity of acute MI. Based on clearly defined criteria the guidelines attempt to provide clinically active physicians with assistance in the diagnosis and treatment of this specific disease. Nevertheless, it is still necessary to take a holistic view of the patient with all the individual characteristics.

Exosomes derived from mesenchymal stem cells inhibit neointimal hyperplasia by activating the Erk1/2 signalling pathway in rats

Background

Restenosis is a serious problem in patients who have undergone percutaneous transluminal angioplasty. Endothelial injury resulting from surgery can lead to endothelial dysfunction and neointimal formation by inducing aberrant proliferation and migration of vascular smooth muscle cells. Exosomes secreted by mesenchymal stem cells have been a hot topic in cardioprotective research. However, to date, exosomes derived from mesenchymal stem cells (MSC-Exo) have rarely been reported in association with restenosis after artery injury. The aim of this study was to investigate whether MSC-Exo inhibit neointimal hyperplasia in a rat model of carotid artery balloon-induced injury and, if so, to explore the underlying mechanisms.

Methods

Characterization of MSC-Exo immunophenotypes was performed by electron microscopy, nanoparticle tracking analysis and western blot assays. To investigate whether MSC-Exo inhibited neointimal hyperplasia, rats were intravenously injected with normal saline or MSC-Exo after carotid artery balloon-induced injury. Haematoxylin-eosin staining was performed to examine the intimal and media areas. Evans blue dye staining was performed to examine re-endothelialization. Moreover, immunohistochemistry and immunofluorescence were performed to examine the expression of CD31, vWF and α-SMA. To further investigate the involvement of MSC-Exo-induced re-endothelialization, the underlying mechanisms were studied by cell counting kit-8, cell scratch, immunofluorescence and western blot assays.

Results

Our data showed that MSC-Exo were ingested by endothelial cells and that systemic injection of MSC-Exo suppressed neointimal hyperplasia after artery injury. The Evans blue staining results showed that MSC-Exo could accelerate re-endothelialization compared to the saline group. The immunofluorescence and immunohistochemistry results showed that MSC-Exo upregulated the expression of CD31 and vWF but downregulated the expression of α-SMA. Furthermore, MSC-Exo mechanistically facilitated proliferation and migration by activating the Erk1/2 signalling pathway. The western blot results showed that MSC-Exo upregulated the expression of PCNA, Cyclin D1, Vimentin, MMP2 and MMP9 compared to that in the control group. Interestingly, an Erk1/2 inhibitor reversed the expression of the above proteins.

Conclusion

Our data suggest that MSC-Exo can inhibit neointimal hyperplasia after carotid artery injury by accelerating re-endothelialization, which is accompanied by activation of the Erk1/2 signalling pathway. Importantly, our study provides a novel cell-free approach for the treatment of restenosis diseases after intervention.