Platelets in Vascular Calcification: A Comprehensive Review of Platelet-Derived Extracellular Vesicles, Protein Interactions, Platelet Function Indices, and their Impact on Cellular Crosstalk.

Vascular calcification (VC) commonly accompanies the development of atherosclerosis, defined by the accumulation of calcium in the arterial wall, potentially leading to stroke and myocardial infarction. Severe and unevenly distributed calcification poses challenges for interventional procedures, elevating the risks of vascular dissection, acute vascular occlusion, restenosis, and other major adverse cardiovascular events. Platelets promote the development of atherosclerosis by secreting various inflammatory mediators, regulating cell migration, aggregation, adhesion, and initiating and expanding inflammatory responses. There is emerging evidence that platelets play a direct role in VC; however, this novel concept has not yet been critically assessed. This review describes the intricate mechanisms by which platelets promote VC, focusing on three key aspects and the potential opportunities for their therapeutic targeting: extracellular vesicles, platelet-regulatory proteins, and indices related to platelet function.

Performance of heart rate adjusted heart rate variability for risk stratification of sudden cardiac death.

PURPOSE: As a non-invasive tool for the assessment of cardiovascular autonomic function, the predictive value of heart rate variability (HRV) for sudden cardiac death (SCD) risk stratification remains unclear. In this study, we investigated the performance of the individualized heart rate (HR) adjusted HRV (HRVI) for SCD risk stratification in subjects with diverse risks. METHODS: A total of 11 commonly used HRV metrics were analyzed in 192 subjects, including 88 healthy controls (low risk group), 82 hypertrophic cardiomyopathy (HCM) patients (medium risk group), and 22 SCD victims (high risk group). The relationship between HRV metrics and HR was examined with long-term and short-term analysis. The performance HRVI was evaluated by area under the receiver operating characteristic curve (AUC) and covariance of variation (CV). RESULTS: Most of the HRV metrics were exponentially decayed with the increase of HR, while the exponential power coefficients were significantly different among groups. The HRVI metrics discriminated low, medium and high risk subjects with a median AUC of 0.72[0.11], which was considerably higher than that of the traditional long-term (0.63[0.04]) and short-term (0.58[0.05]) HRV without adjustment. The average CV of the HRVI metrics was also significantly lower than traditional short-term HRV metrics (0.09 ± 0.02 vs. 0.24 ± 0.13, p < 0.01). CONCLUSIONS: Subjects with diverse risks of SCD had similar exponential decay relationship between HRV metrics and HR, but with different decaying rates. HRVI provides reliable and robust estimation for risk stratification of SCD.

Efficacy and Safety of Aspirin Combined with Low-Dose P2Y12 Receptor Antagonists in East Asian Patients Undergoing PCI.

Previous studies have indicated that low-dose new generation of P2Y12 receptor antagonists may be more suitable compared with clopidogrel at a standard dose for the dual antiplatelet therapy (DAPT) for East Asian patients receiving percutaneous coronary intervention (PCI). However, there remains no consensus in clinical practice. Thus, in this study, we aimed to determine the efficacy and safety of low-dose P2Y12 receptor antagonists, compared to clopidogrel at a standard dose, in DAPT in East Asian patients after PCI. We systematically searched literatures for randomized controlled trials (RCT) comparing low-dose P2Y12 receptor antagonists with standard-dose clopidogrel for the treatment of East Asian patients undergoing PCI. The endpoints of efficacy include major adverse cardiac events (MACEs), all-cause mortality, and the number of target vessel revascularization. The indicators of safety include major and minor bleeding events. Heterogeneity was evaluated by I2 statistic test. Begg's and Egger's tests were used to evaluate publication bias. In total, 2,747 subjects from 8 RCT studies were included. Low-dose new P2Y12 receptor antagonists, that is, ticagrelor or prasugrel, showed significantly lower incidence of MACEs, as compared with standard-dose clopidogrel, in the East Asian patients who are in DAPT after undergoing PCI. Further, no difference was noted for the risk of major and minor bleeding events. In East Asian patients undergoing PCI and receiving DAPT, the use of low-dose P2Y12 receptor antagonists, ticagrelor or prasugrel, has been determined to be superior than clopidogrel at standard dose; this has been evidenced by a lower incidence of MACEs without increasing the risk of bleeding.

Association between heart rate variability indices and features of spontaneous ventricular tachyarrhythmias in mice.

Direct evidence is limited for the association between heart rate variability (HRV) indices and ventricular tachyarrhythmias (VTAs). While galectin-3 (Gal-3) is regarded as a causal factor for cardiac remodelling and a biomarker for arrhythmias, its regulation on VTAs and HVR is unknown. Using aged transgenic (TG) mice with cardiac overexpression of ß2 -adrenoceptors and spontaneous VTAs, we studied whether changes in HRV indices correlated with the severity of VTAs, and whether Gal-3 gene knockout (KO) in TG mice might limit VTA. Body-surface ECG was recorded (10-minute period) in 9- to 10-month-old mice of non-transgenic (nTG), TG and TG × Gal-3 knockout (TG/KO). Time-domain, frequency-domain and nonlinear-domain HRV indices were calculated using the R-R intervals extracted from ECG signals and compared with frequency of VTAs. TG and TG/KO mice developed frequent VTAs and showed significant changes in certain time-domain and nonlinear-domain HRV indices relative to nTG mice. The severity of VTAs in TG and TG/KO mice in combination, estimated by VTA counts and arrhythmia score, was significantly correlated with certain time-domain and nonlinear-domain HRV indices. In conclusion, significant changes in HRV indices were evident and correlated with the severity of spontaneous VTAs in TG mice. The frequency of VTA and HRV indices were largely comparable between TG and TG/KO mice. Deletion of Gal-3 in TG mice altered certain HRV indices implying influence by neuronally localized Gal-3 on autonomic nervous activity.

Activation of the STAT3/microRNA-21 pathway participates in angiotensin II-induced angiogenesis.

Angiotensin II (AngII) facilitates angiogenesis that is associated with the continuous progression of atherosclerotic plaques, but the underlying mechanisms are still not fully understood. Several microRNAs (miRNAs) have been shown to promote angiogenesis; however, whether miRNAs play a crucial role in AngII-induced angiogenesis remains unclear. This study evaluated the functional involvement of miRNA-21 (miR-21) in the AngII-mediated proangiogenic response in human microvascular endothelial cells (HMECs). We found that AngII exerted a proangiogenic role, indicated by the promotion of proliferation, migration, and tube formation in HMECs. Next, miR-21 was found to be upregulated in AngII-treated HMECs, and its specific inhibitor potently blocked the proangiogenic effects of AngII. Subsequently, we focused on the constitutive activation of STAT3 in the AngII-mediated proangiogenic process. Bioinformatic analysis indicated that STAT3 acted as a transcription factor initiating miR-21 expression, which was verified by ChIP-PCR. A reporter assay further identified three functional binding sites of STAT3 in the miR-21 promoter region. Moreover, phosphatase and tensin homolog (PTEN) was recognized as a target of miR-21, and STAT3 inhibition restored AngII-induced reduction in PTEN. Similarly, the STAT3/miR-21 axis was shown to mediate AngII-provoked angiogenesis in vivo, which was demonstrated by using the appropriate inhibitors. Our data suggest that AngII was involved in proangiogenic responses through miR-21 upregulation and reduced PTEN expression, which was, at least in part, linked to STAT3 signaling. The present study provides novel insights into AngII-induced angiogenesis and suggests potential treatment strategies for attenuating the progression of atherosclerotic lesions and preventing atherosclerosis complications.

Roles of High Mobility Group Box 1 in Cardiovascular Calcification.

Calcific disease of the cardiovascular system, including atherosclerotic calcification, medial calcification in diabetes and calcific aortic valve disease, is an important risk factor for many adverse cardiovascular events such as ischemic cardiac events and subsequent mortality. Although cardiovascular calcification has long been considered to be a passive degenerative occurrence, it is now recognized as an active and highly regulated process that involves osteochondrogenic differentiation, apoptosis and extracellular vesicle release. Nonetheless, despite numerous studies on the pathogenesis of cardiovascular calcification, the underlying mechanisms remain poorly understood. High mobility group box 1 (HMGB1), a nuclear protein bound to chromatin in almost all eukaryotic cells, acts as a damage-associated molecular pattern (DAMP) when released into the extracellular space upon cell activation, injury or death. Moreover, HMGB1 also functions as a bone-active cytokine participating in bone remodeling and ectopic calcification pathogenesis. However, studies on the roles of HMGB1 in promoting cardiovascular calcification are limited to date, and the mechanisms involved are still unclear. In this review, we summarize recent studies investigating the mechanism of cardiovascular calcification and discuss multiple roles of HMGB1 in its development.

Up-Regulated Expression of Matrix Metalloproteinases in Endothelial Cells Mediates Platelet Microvesicle-Induced Angiogenesis.

BACKGROUND/AIMS: Platelet microvesicles (PMVs) contribute to angiogenesis and vasculogenesis, but the mechanisms underlying these contributions have not been fully elucidated. In the present study, we investigated whether PMVs regulate the angiogenic properties of endothelial cells (ECs) via mechanisms extending beyond the transport of angiogenic regulators from platelets. METHODS: In vitro Matrigel tube formation assay and in vivo Matrigel plug assay were used to evaluate the pro-angiogenic activity of PMVs. The effects of PMVs on the migration of human umbilical vein endothelial cells (HUVECs) were detected by transwell assay and wound-healing assay. Real-time PCR and western blot were conducted to examine mRNA and protein expression of pro-angiogenic factors in HUVECs. Matrix metalloproteinase (MMP) activity was assayed by gelatin zymography. Moreover, the effects of specific MMP inhibitors were tested. RESULTS: PMVs promoted HUVEC capillary-like network formation in a dose-dependent manner. Meanwhile, PMVs dose-dependently facilitated HUVEC migration. Levels of MMP-2 and MMP-9 expression and activity were up-regulated in HUVECs stimulated with PMVs. Inhibition of MMPs decreased their pro-angiogenic and pro-migratory effects on HUVECs. Moreover, we confirmed the pro-angiogenic activity of PMVs in vivo in mice with subcutaneous implantation of Matrigel, and demonstrated that blockade of MMPs attenuated PMV-induced angiogenesis. CONCLUSION: The findings of our study indicate that PMVs promote angiogenesis by up-regulating MMP expression in ECs via mechanism extending beyond the direct delivery of angiogenic factors.

Intracoronary electrocardiogram during alcohol septal ablation for hypertrophic obstructive cardiomyopathy predicts myocardial injury size.

Alcohol septal ablation (ASA) has been used widely to treat patients with hypertrophic obstructive cardiomyopathy (HOCM). During the routine ASA procedure, it is difficult to detect the septal injury in real-time. The aim of the present study is to assess myocardial injury during ASA by recording intracoronary electrocardiogram (IC-ECG). From 2012 to 2015, 31 HOCM patients were treated with ASA, and IC-ECG was recorded in 21 patients successfully before and after ethanol injection. The elevation of ST-segment on IC-ECG after ethanol injection was expressed as its ratio to the level before injection or the absolute increasing value. Blood samples were collected before and after ASA for measuring changes in cardiac biomarkers. The ratio value of ST-segment elevation was positively correlated with both the amount of ethanol injected (r = 0.645, P = 0.001) and the myocardial injury size (creatine kinase-MB area under the curve (AUC) of CK-MB) (r = 0.466, P = 0.017). The absolute increment of ST-segment was also positively associated with both the amount of ethanol (r = 0.665, P = 0.001) and AUC of CK-MB (0.685, P = 0.001). However, there was no statistical correlation between the reduction of left ventricular outflow tract gradient and ST-segment elevation. Additionally no severe ASA procedure-related complications were observed in our patients. In conclusion, myocardial injury induced by ethanol injection can be assessed immediately by ST-segment elevation on IC-ECG. This study is the first to show that IC-ECG is a useful method for predicting myocardial injury during ASA in real-time.

Melatonin ameliorates atherosclerosis by suppressing S100a9-mediated vascular inflammation.

Atherosclerosis (AS)-associated cardiovascular diseases are predominant causes of morbidity and mortality worldwide. Melatonin, a circadian hormone with anti-inflammatory activity, may be a novel therapeutic intervention for AS. However, the exact mechanism is unclear. This research intended to investigate the mechanism of melatonin in treating AS. Melatonin (20 mg/kg/d) was intraperitoneally administered in a high-fat diet (HFD)-induced AS model using apolipoprotein E-deficient (ApoE-/-) mice for 12 weeks. Immunohistochemical and immunofluorescence analyses, data-independent acquisition (DIA)-based protein profiling, ingenuity pathway analysis (IPA), and western blotting were employed to investigate the therapeutic effects of melatonin in treating HFD-induced AS. An adeno-associated virus (AAV) vector was further used to confirm the antiatherosclerotic mechanism of melatonin. Melatonin treatment markedly attenuated atherosclerotic lesions, induced stable phenotypic sclerotic plaques, inhibited macrophage infiltration, and suppressed the production of proinflammatory cytokines in ApoE-/- mice with HFD-induced AS. Notably, DIA-based quantitative proteomics together with IPA identified S100a9 as a pivotal mediator in the protective effects of melatonin. Moreover, melatonin significantly suppressed HFD-induced S100a9 expression at both the mRNA and protein levels. The overexpression of S100a9 significantly activated the NF-κB signaling pathway and markedly abolished the antagonistic effect of melatonin on HFD-induced vascular inflammation during atherogenesis. Melatonin exerts a significant antiatherogenic effect by inhibiting S100a9/NF-κB signaling pathway-mediated vascular inflammation. Our findings reveal a novel antiatherosclerotic mechanism of melatonin and underlie its potential clinical use in modulating AS with good availability and affordability.

A Multi-Bioactive Nanomicelle-Based "One Stone for Multiple Birds" Strategy for Precision Therapy of Abdominal Aortic Aneurysms.

Abdominal aortic aneurysm (AAA) remains a lethal aortic disease in the elderly. Currently, no effective drugs can be clinically applied to prevent the development of AAA. Herein, a "one stone for multiple birds" strategy for AAA therapy is reported. As a proof of concept, three bioactive conjugates are designed and synthesized, which can assemble into nanomicelles. Cellularly, these nanomicelles significantly inhibit migration and activation of inflammatory cells as well as protect vascular smooth muscle cells (VSMCs) from induced oxidative stress, calcification and apoptosis, with the best effect for nanomicelles (TPTN) derived from a conjugate defined as TPT. After intravenous delivery, TPTN efficiently accumulates in the aneurysmal tissue of AAA rats, showing notable distribution in neutrophils, macrophages and VSMCs, all relevant to AAA pathogenesis. Whereas three examined nanomicelles effectively delay expansion of AAA in rats, TPTN most potently prevents AAA growth by simultaneously normalizing the pro-inflammatory microenvironment and regulating multiple pathological cells. TPTN is effective even at 0.2 mg kg-1 . Besides, TPTN can function as a bioactive nanoplatform for site-specifically delivering and triggerably releasing anti-aneurysmal drugs, affording synergistic therapeutic effects. Consequently, TPTN is a promising multi-bioactive nanotherapy and bioresponsive targeting delivery nanocarrier for effective therapy of AAA and other inflammatory vascular diseases.

Pulmonary circulation-mediated heart targeting for the prevention of heart failure by inhalation of intrinsically bioactive nanoparticles.

Heart failure is a serious clinical and public health problem. Currently there is an unmet demand for effective therapies for heart failure. Herein we reported noninvasive inhalation delivery of nanotherapies to prevent heart failure. Methods: A reactive oxygen species (ROS)-scavenging material (TPCD) was synthesized, which was processed into antioxidative and anti-inflammatory nanoparticles (i.e., TPCD NP). By decoration with a mitochondrial-targeting moiety, a multilevel targeting nanotherapy TTPCD NP was engineered. Pulmonary accumulation of inhaled TPCD NP and underlying mechanisms were examined in mice. In vivo efficacies of nanotherapies were evaluated in mice with doxorubicin (DOX)-induced cardiomyopathy. Further, an antioxidative, anti-inflammatory, and pro-resolving nanotherapy (i.e., ATTPCD NP) was developed, by packaging a peptide Ac2-26. In vitro and in vivo efficacies of ATTPCD NP were also evaluated. Results: TPCD NP alleviated DOX-induced oxidative stress and cell injury by internalization in cardiomyocytes and scavenging overproduced ROS. Inhaled TPCD NP can accumulate in the heart of mice by transport across the lung epithelial and endothelial barriers. Correspondingly, inhaled TPCD NP effectively inhibited DOX-induced heart failure in mice. TTPCD NP showed considerably enhanced heart targeting capability, cellular uptake efficiency, and mitochondrial localization capacity, thereby potentiating therapeutic effects. Notably, TPCD NP can serve as bioactive and ROS-responsive nanovehicles to achieve combination therapy with Ac2-26, affording further enhanced efficacies. Importantly, inhaled TPCD NP displayed good safety at a dose 5-fold higher than the efficacious dose. Conclusions: Inhalation delivery of nanoparticles is an effective, safe, and noninvasive strategy for targeted treatment of heart diseases. TPCD NP-based nanotherapies are promising drugs for heart failure and other acute/chronic heart diseases associated with oxidative stress.

Liver X receptor agonist methyl-3ß-hydroxy-5α,6α-epoxycholanate attenuates atherosclerosis in apolipoprotein E knockout mice without increasing plasma triglyceride.

BACKGROUND: Liver X receptors (LXRs) promote macrophage reverse cholesterol transport and cholesterol excretion from the body. The synthetic LXR ligands T0901317 and GW3965 were shown to significantly inhibit atherosclerosis in mice and to increase the expression of ATP-binding cassette transporter A1 (ABCA1) in the atherosclerotic lesions. However, these compounds increase plasma and hepatic triglyceride (TG) levels in mice. Methyl-3ß-hydroxy-5α,6α-epoxycholanate (MHEC), synthesized from hyodeoxycholic acid, functions as an LXR agonist, but its role in atherogenesis and lipid metabolism remained to be elucidated. METHODS: THP-1-derived macrophages were cultured in the medium con- taining various concentrations of MHEC or T0901317 (0-10 µmol/l) for 24 h. Reverse transcription polymerase chain reaction was used to quantify LXRα, LXRß and ABCA1 mRNA levels in macrophages. Additionally, MHEC or T0901317 was orally administered at 10 mg/kg daily for 6 weeks in apolipoprotein E knockout (apoE⁻/⁻) mice fed a high-cholesterol diet. Plasma lipids were determined enzymatically. The area of and ABCA1 expression in the aortic atherosclerotic lesions were measured by oil red O staining and immunohistochemistry, respectively. RESULTS: Both MHEC and T0901317 equally stimulated LXRα and ABCA1 mRNA expression in a dose-dependent manner in THP-1-derived macrophages, but they did not induce LXRß mRNA expression significantly. The plasma levels of total cholesterol, TG and high-density lipoprotein cholesterol were significantly higher in T0901317-treated mice than in the vehicle-treated control group. Interestingly, MHEC treatment dramatically increased plasma high-density lipoprotein cholesterol without altering plasma levels of total cholesterol and TG. Both MHEC and T0901317 equally inhibited the development of atherosclerotic lesions in apoE⁻/⁻ mice. The expression of ABCA1, a cholesterol efflux transporter, was greatly induced by the two LXR agonists in the artery wall. CONCLUSIONS: MHEC is a novel LXR agonist and it inhibits atherosclerosis in apoE⁻/⁻ mice without raising blood TG. Thus, MHEC relative to T0901317 may be a better therapeutic LXR agonist for the treatment of atherosclerosis.

Revascularization may accelerate renal dysfunction in hypertensive patients with moderate atherosclerotic stenosis of renal arteries.

Atherosclerotic renal artery stenosis (ARAS) accounts for more than 90% of cases with renal artery stenosis, which is the recognized cause of secondary hypertension, renal dysfunction and acute pulmonary edema. It is estimated that about 15% of patients with hypertension also have different degrees of ARAS at the same time. Hypertension is known to be associated with the risk of atherosclerotic vascular disease; these two conditions usually co-exist and interact with each other. At present, many studies have focused on how to intervene ARAS correctly or just optimal medical therapy (OMT). For patients with severe ARAS, stent implantation seems to be able to receive better clinical benefits because it can avoid renal ischemic injury; however, it remains inconclusive whether stent implantation is suitable for the essential hypertension patients accompanied with mild to moderate ARAS. We speculate that renal artery revascularization may accelerate renal dysfunction in essential hypertensive patients accompanied with mild to moderate ARAS, especially when hypertension could not be controlled within the normal range after the revascularization.

Post-infarct left ventricular thrombosis is mechanistically related to ventricular wall rupture.

Left ventricular thrombus (LVT) after acute myocardial infarction (AMI) remains to be a common complication bearing adverse prognostic implication. Majority of LVT occurs within the first week after AMI. Over decades, the regional stasis of blood flow is regarded as the main reason for LVT formation. Here we hypothesize that LVT developed within the first week after AMI is the consequence of an incomplete wall rupture. Endocardial rupture with exposure of infarcted tissues triggers platelet thrombosis within the rupture site and then the thrombus grows towards the ventricular chamber forming LVT. This hypothesis is implicated by the comparable clinical features of patients with LVT or with cardiac rupture, and supported by experimental findings in murine model of AMI revealing the mechanistic link between rupture and LVT. This hypothesis, if confirmed, would improve our understanding on the pathophysiology of both rupture and LVT as two pivotal mechanical complications after AMI, and the role of platelets in the setting of AMI and hence the use of anti-platelet therapies. Future studies are warranted to test this hypothesis by serial cardiac imaging on AMI patients with high risk of LVT.

Tailored Interventions to Improve Medication Adherence for Cardiovascular Diseases.

Over the past half-century, medical research on cardiovascular disease (CVD) has achieved a great deal; however, medication adherence is unsatisfactory. Nearly 50% of patients do not follow prescriptions when taking medications, which limits the ability to maximize their therapeutic effects and results in adverse clinical outcomes and high healthcare costs. Furthermore, the effects of medication adherence interventions are disappointing, and tailored interventions have been proposed as an appropriate way to improve medication adherence. To rethink and reconstruct methods of improving medication adherence for CVD, the literature on tailored interventions for medication adherence focusing on CVD within the last 5 years is retrieved and reviewed. Focusing on identifying nonadherent patients, detecting barriers to medication adherence, delivering clinical interventions, and constructing theories, this article reviews the present state of tailored interventions for medication adherence in CVD and also rethinks the present difficulties and suggests avenues for future development.

A pH/ROS dual-responsive and targeting nanotherapy for vascular inflammatory diseases.

Cardiovascular diseases (CVDs) remain the leading cause of morbidity and mortality worldwide. Vascular inflammation is closely related to the pathogenesis of a diverse group of CVDs. Currently, it remains a great challenge to achieve site-specific delivery and controlled release of therapeutics at vascular inflammatory sites. Herein we hypothesize that active targeting nanoparticles (NPs) simultaneously responsive to low pH and high levels of reactive oxygen species (ROS) can serve as an effective nanoplatform for precision delivery of therapeutic cargoes to the sites of vascular inflammation, in view of acidosis and oxidative stress at inflamed sites. The pH/ROS dual-responsive NPs were constructed by combination of a pH-sensitive material (ACD) and an oxidation-responsive material (OCD) that can be facilely synthesized by chemical functionalization of ß-cyclodextrin, a cyclic oligosaccharide. Simply by regulating the weight ratio of ACD and OCD, the pH/ROS responsive capacity can be easily modulated, affording NPs with varied hydrolysis profiles under inflammatory microenvironment. Using rapamycin (RAP) as a candidate drug, we first demonstrated in vitro therapeutic advantages of RAP-containing NPs with optimal dual-responsive capability, i.e. RAP/AOCD NP, and a non-responsive nanotherapy (RAP/PLGA NP) and two single-responsive nanotherapies (RAP/ACD NP and RAP/OCD NP) were used as controls. In an animal model of vascular inflammation in rats subjected to balloon injury in carotid arteries, AOCD NP could accumulate at the diseased site after intravenous (i.v.) injection. Consistently, i. v. treatment with RAP/AOCD NP more effectively inhibited neointimal hyperplasia in rats with induced arterial injuries, compared to RAP/PLGA NP, RAP/ACD NP, and RAP/OCD NP. By surface decoration of AOCD NP with a peptide (KLWVLPKGGGC) targeting type IV collagen (Col-IV), the obtained Col-IV targeting, dual-responsive nanocarrier TAOCD NP showed dramatically increased accumulation at injured carotid arteries. Furthermore, RAP/TAOCD NP exhibited significantly potentiated in vivo efficacy in comparison to the passive targeting nanotherapy RAP/AOCD NP. Importantly, in vitro cell culture experiments and in vivo animal studies in both mice and rats revealed good safety for AOCD NP and RAP/AOCD NP, even after long-term treatment via i. v. injection. Consequently, our results demonstrated that the newly developed Col-IV targeting, pH/ROS dual-responsive NPs may serve as an effective and safe nanovehicle for precision therapy of arterial restenosis and other vascular inflammatory diseases.

Luminescence Imaging of Acute Liver Injury by Biodegradable and Biocompatible Nanoprobes.

Liver injury can result in different hepatic diseases such as fatty liver, liver fibrosis, hepatitis, and liver failure, which are mainly responsible for global mortality and morbidity. Early diagnosis is critical for the treatment of liver diseases. Herein we report luminescence imaging of neutrophil-mediated acute liver injury, including alcoholic liver injury (ALI) and acute liver failure (ALF). To this purpose, a biodegradable luminescent material was developed by chemical functionalization of a cyclic oligosaccharide, which can be produced into nanoprobes (defined as LaCD NPs). Luminescence of LaCD NPs was dependent on the level of reactive oxygen species and myeloperoxidase (MPO). Correspondingly, activated neutrophils could be specifically imaged by LaCD NPs, and the luminescent signal was positively associated with the neutrophil count. In mouse models of ALI and ALF, LaCD NPs enabled precise quantification and tracking of neutrophils in livers. In both cases, changes in the luminescence intensity are consistent with time-dependent profiles of neutrophils, MPO, and other parameters relevant to the pathogenesis of liver injury. Moreover, the luminescence imaging capacity of LaCD NPs can be additionally improved by surface functionalization with a neutrophil-targeting peptide. In addition, preliminary in vitro and in vivo studies demonstrated good safety of LaCD NPs. Consequently, LaCD NPs can be further developed as an effective and biocompatible luminescent nanoprobe for in vivo dynamic detection of the development of neutrophil-mediated acute liver injury. It is also promising for diagnosis of other neutrophil-associated liver diseases.

Celastrol, a triterpene extracted from Tripterygium wilfordii Hook F, inhibits platelet activation.

Celastrol is an active ingredient of the traditional Chinese medicinal plant, Tripterygium wilfordii Hook F, which is known especially for its anti-inflammatory effects. However, on the cellular and molecular levels, celastrol's mechanism of action is only poorly understood. Because platelets contribute to inflammatory events, this study investigates the effects of celastrol on platelet function using flow cytometry, aggregometry, and adhesion assays. In in vitro experiments with human platelets, celastrol inhibits adenosine-5-diphosphate (ADP)-induced expression of the platelet activation marker P-selectin and glycoprotein IIb/IIIa activation with 50% inhibition values of 1.62 and 1.86 microM, respectively. Celastrol also inhibits thrombin-stimulated and phorbol 12-myristate 13-acetate-stimulated P-selectin expression on platelets. Furthermore, ADP-stimulated platelet adhesion on fibrinogen is partially prevented by 5 microM celastrol. In platelet aggregometry, celastrol (0.05-0.5 mM) inhibits ADP-induced aggregation of platelet-rich plasma. Moreover, 12 male C57BL/6J mice were randomly grouped to receive intraperitoneal treatment with either celastrol (2 mg x kg x day) or vehicle. After 4 weeks of the respective treatment, celastrol inhibited 2 and 20 microM ADP-stimulated platelet fibrinogen binding by 34.5% (P < 0.01) and 28.9% (P < 0.05), respectively, compared with controls. In conclusion, these results indicate that celastrol exerts inhibitory effects on platelets. This new finding contributes to the understanding of antithrombotic and also anti-inflammatory effects of celastrol.

Clinical efficiency and safety analysis of transcatheter closure of multiple atrial septal defects in adults.

BACKGROUND: Transcatheter closure of atrial septal defects (ASDs) is currently a reliable alternative to surgery, even though challenging in patients with multiple ASDs. HYPOTHESIS: The aim of this study was to evaluate the clinical efficiency and safety of transcatheter closure in multiple ASDs. METHODS: Multiple ASDs were diagnosed by transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE). The occlusive condition and distance between 2 adjacent ASDs were measured by TTE examination. Then, the number and size of the occluder(s) was determined. TTE examinations were performed after transcatheter closure as follow-up. RESULTS: The transcatheter procedure was successful in 15 patients with multiple ASDs, using a single occluder in 9 patients and 2 occluders in the remaining 6 patients. Overall, 21 ASD occluders were implanted. During a follow-up period of 6 mo to 5 y, a slight residual shunt was found in 1 patient without any symptoms; a moderate residual shunt was identified at the inferior vena cava and the occluder was removed by surgery 1 mo after procedure. Other complications, including endocarditis, arrhythmia, thromboembolism, and atrioventricular valve damage were not recorded in any of the 15 patients during the follow-up period. CONCLUSION: Transcatheter closure of multiple ASDs is safe and efficient. Two occluders are necessary for the distance of 2 ASDs more than 7 mm, and a single occluder is sufficient for those 7 mm or less.

Stimulation of ß-adrenoceptors up-regulates cardiac expression of galectin-3 and BIM through the Hippo signalling pathway.

BACKGROUND AND PURPOSE: Expression of the pro-fibrotic galectin-3 and the pro-apoptotic BIM is elevated in diseased heart or after ß-adrenoceptor stimulation, but the underlying mechanisms are unclear. This question was addressed in the present study. EXPERIMENTAL APPROACH: Wild-type mice and mice with cardiac transgenic expression of ß2 -adrenoceptors, mammalian sterile-20 like kinase 1 (Mst1) or dominant-negative Mst1, and non-specific galectin-3 knockout mice were used. Effects of the ß-adrenoceptor agonist isoprenaline or ß-adrenoceptor antagonists were studied. Rat cardiomyoblasts (H9c2) were used for mechanistic exploration. Biochemical assays were performed. KEY RESULTS: Isoprenaline treatment up-regulated expression of galectin-3 and BIM, and this was inhibited by non-selective or selective ß-adrenoceptor antagonists (by 60-70%). Cardiac expression of galectin-3 and BIM was increased in ß2 -adrenoceptor transgenic mice. Isoprenaline-induced up-regulation of galectin-3 and BIM was attenuated by Mst1 inactivation, but isoprenaline-induced galectin-3 expression was exaggerated by transgenic Mst1 activation. Pharmacological or genetic activation of ß-adrenoceptors induced Mst1 expression and yes-associated protein (YAP) phosphorylation. YAP hyper-phosphorylation was also evident in Mst1 transgenic hearts with up-regulated expression of galectin-3 (40-fold) and BIM as well as up-regulation of many YAP-target genes by RNA sequencing. In H9c2 cells, isoprenaline induced YAP phosphorylation and expression of galectin-3 and BIM, effects simulated by forskolin but abolished by PKA inhibitors, and YAP knockdown induced expression of galectin-3 and BIM. CONCLUSIONS AND IMPLICATIONS: Stimulation of cardiac ß-adrenoceptors activated the Mst1/Hippo pathway leading to YAP hyper-phosphorylation with enhanced expression of galectin-3 and BIM. This signalling pathway would have therapeutic potential. LINKED ARTICLES: This article is part of a themed section on Adrenoceptors-New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc.