Apolipoprotein J as a predictive biomarker for restenosis after carotid endarterectomy: a retrospective study

Clusterin, paraoxonase 1, and myeloperoxidase alterations induce high-density lipoproteins dysfunction and contribute to peripheral artery disease; aggravation by type 2 diabetes mellitus

Peripheral artery disease (PAD) is an atherosclerotic disorder affecting arteries of the lower limbs, the major risk factors including dyslipidemia and diabetes mellitus (DM). We aimed to identify alterations of the proteins in high-density lipoproteins (HDL) associated with HDL dysfunction in PAD patients. HDL₂ and HDL₃ were isolated from plasma of PAD patients with/without DM (PAD-DM/PAD) and healthy subjects (N). Apolipoprotein AI (ApoAI), ApoAII, ApoCIII, clusterin (CLU), paraoxonase 1 (PON1), myeloperoxidase (MPO), and ceruloplasmin (CP) were measured in HDL₂ /HDL₃ and plasma. Oxidation and glycation of the analyzed proteins were assessed as malondialdehyde-protein adducts (MDA) and advanced glycation end-products (AGE), respectively. The anti-inflammatory effect of HDL₃ was estimated as its potential to reduce monocyte adhesion to tumor necrosis factor α-activated endothelial cells. We show that in PAD patients compared to N subjects: (i) HDL₂ presented increased levels of MDA-PON1, AGE-PON1, AGE-ApoAI, ApoAII, ApoCIII, and CP levels, and decreased PON1 levels; (ii) HDL₃ had increased levels of MDA- and AGE-CLU and -ApoAI, MDA-PON1, ApoCIII, CLU, MPO, CP, and reduced PON1 levels. All these alterations were exacerbated by DM. These changes were more pronounced in HDL₃ , which had reduced anti-inflammatory potential in PAD and became pro-inflammatory in PAD-DM. In PAD patients' plasma, CLU levels and MPO specific activity increased, while PON1 specific activity decreased. In conclusion, HDL function is altered in PAD patients due to multiple modifications of associated proteins that are aggravated by DM. Plasma CLU, MPO, and PON1 could constitute indicators of HDL dysfunction and contribute to risk stratification in PAD patients.

Study on the Mechanism of Platelet-Released Clusterins Inducing Restenosis after Carotid Endarterectomy by Activating TLR3/NF-κb p65 Signaling Pathway

This study aimed to explore the role of clusterin released by platelet aggregation in restenosis after carotid endarterectomy. 35 patients who underwent carotid endarterectomy due to carotid artery stenosis were enrolled in this study. They were admitted to the Third Affiliated Hospital of Qiqihar Medical University from January 2018 to January 2019. All the patients were divided into two groups: the restenosis group and the nonrestenosis group, according to the follow-up results within 12 months. Peripheral blood was collected on the first day, 6 months, and 12 months after operation. The expression of CLU in serum of plasma and platelet culture medium was detected by an ELISA experiment. The vascular endothelial cells were cultured in vitro with 100 ng/mL of human recombinant CLU added to the medium. Cell proliferation, migration, and invasion were detected by CCK8, scratch, and Transwell invasion tests. The expression level of TLR3 and NF-κb p65 proteins in cells was detected by western blot. TLR3 knockout plasmids in vascular endothelial cell lines were transfected. Cell proliferation and migration were detected by CCK8 and the scratch assay. The CLU content in peripheral blood plasma and supernatant of platelet culture medium was significantly higher in the restenosis group than that of the control group (p=0.003) 6 months after operation (p=0.047) and 12 months after operation (p=0.011). When CLU was added to vascular endothelial cell culture medium, the proliferation and migration were significantly enhanced. The TLR3/NF-κb p65 protein expression level in cells also significantly increased. After the transfection of TLR3 knockout plasmids into vascular endothelial cell lines, CLU cannot promote the proliferation and migration of vascular endothelial cells. Platelet-released clusterin can induce vascular endothelial cell proliferation and migration by activating the TLR3/NF-kb p65 signaling pathway, leading to carotid artery restenosis after carotid endarterectomy.

A systemic review into carotid plaque features as predictors of restenosis after carotid endarterectomy

OBJECTIVE

Restenosis after carotid endarterectomy (CEA) limits its long-term efficacy for stroke prevention. Thus, it is of utmost importance to identify the factors that predispose a patient to restenosis after CEA. This systemic review aims to survey the current literature regarding restenosis after CEA and discuss the predictive value of carotid plaque features.

METHODS

A systemic review of studies on the predictive value of carotid plaque features for restenosis after CEA was conducted according to the PRISMA guidelines. PubMed/MEDLINE and Embase databases were searched up to March 20, 2020. Two authors independently extracted the data and assessed the risk of bias with the Quality in Prognosis Studies tool. Given the heterogeneity in the measurement of prognostic factors, types of CEA, and clinical outcomes, a qualitative synthesis was performed.

RESULTS

Twenty-one articles with a sample size that ranged from 11 to 1203 were included in this systematic review. Based on the presence of calcification in original carotid plaques, two progression patterns of restenosis were hypothesized: patients with calcified plaques may experience a temporary increase in the intima-media thickness (IMT) followed by a decrease in IMT after CEA, whereas patients with noncalcified plaques may experience a gradual increase in IMT after CEA. Accordingly, patients with a high calcium score may have a high restenosis rate within 6 months after CEA and a low restenosis rate thereafter. Thus, the late restenosis rate in patients with uniformly echogenic plaques was lower than that in patients with uniformly echolucent plaques. Pathologically, a lipid-rich, inflammatory carotid plaque is associated with a decreased risk of restenosis within 1 year after CEA, mainly owing to the relatively mild reactive intimal hyperplasia at the surgical site and active inflammation in the remaining media and adventitia. Molecular predictors for restenosis included a Mannose-binding lectin 2 genotype, preoperative C-reactive protein, serum homocysteine, apolipoprotein J, vitamin C, and telomere length of carotid plaques.

CONCLUSIONS

This review demonstrated that carotid plaque features, including imaging features, cellular composition, and molecular features, are correlated with the risk of restenosis after CEA. A comprehensive evaluation of plaque characteristics may help to stratify the risk of restenosis after CEA.

Clusterin as a potential marker of brain ischemia-reperfusion injury in patients undergoing carotid endarterectomy

Introduction: Carotid endarterectomy (CEA) is a surgical procedure used in the prevention of ischemic stroke. However, this procedure can cause complications of ischemia-reperfusion injury to the brain. Clusterin (CLU) is a cytoprotective chaperone protein that is released from neurons in response to various neurological injuries. The objective of the study was to report the changes in serum CLU concentrations of patients undergoing CEA. Materials and methods: The study involved 25 patients with severe internal carotid artery stenosis. Serum samples were taken from patients at three different times: within 24 hours preoperatively to CEA, 12 hours postoperatively, and 48 hours postoperatively. Serum CLU concentrations were measured using a commercially available enzyme-linked immunosorbent assay. Results: When compared to concentrations preoperatively, the serum CLU concentration initially decreased during the 12 hours following CEA. However, 48 hours following the procedure there was an increase in the CLU concentration. After statistical analysis, differences were detected in serum CLU concentration between all three recorded measurements (P < 0.05). Conclusion: Data from our study indicate that serum CLU concentrations are affected after CEA. We hypothesize that serum CLU concentrations may depend on brain ischemia-reperfusion injury following this surgical procedure.