Oxidized low-density lipoprotein-induced microparticles promote endothelial monocyte adhesion via intercellular adhesion molecule 1.

Oxidized low-density lipoprotein (oxLDL) accumulates early in atherosclerotic lesions and plays an important role in the progressive formation of atherosclerotic plaques. Endothelial derived microparticles (EMPs) form a heterogeneous population of <1-µm particles that shed from endothelial membranes upon activation. While EMPs are shown to be involved in atherosclerotic pathophysiology and progression, there is no report regarding the relationship between oxLDL and EMPs. In this study, we aim to determine the influence of oxLDL on endothelial microparticle release and the subsequent regulation of the endothelial activation. EMPs were collected from the medium of human umbilical vein endothelial cells (HUVECs) treated with oxLDL or PBS as control. We find that oxLDL increases the release of EMPs containing intercellular adhesion molecule 1 (ICAM-1) but not vascular cell adhesion molecule 1 (VCAM-1). Confocal microscopy analysis further demonstrates that these EMPs interact with endothelial cells and increase the expression of ICAM-1 in HUVECs. The fact that injecting oxLDL-induced EMPs via the tail vein of ICR mice augments ICAM-1 expression on aortic endothelial cells confirms our results in vivo. Finally, oxLDL-induced EMPs from HUVECs increase the adhesion of monocytes to endothelial cells as determined by the adhesion assay. Our study suggests that oxLDL may augment the release of EMPs harboring increased levels of ICAM-1 that can be transferred to endothelial cells elsewhere. This leads to increased monocyte recruitment in other regions where oxLDL accumulation was initially more limited. EMPs may therefore serve as the mediator that propagates oxLDL-induced endothelial inflammation.

Myeloperoxidase-oxidized high density lipoprotein impairs atherosclerotic plaque stability by inhibiting smooth muscle cell migration.

BACKGROUND: High density lipoprotein (HDL) has been proved to be a protective factor for coronary heart disease. Notably, HDL in atherosclerotic plaques can be nitrated (NO2-oxHDL) and chlorinated (Cl-oxHDL) by myeloperoxidase (MPO), likely compromising its cardiovascular protective effects. METHOD: Here we determined the effects of NO2-oxHDL and Cl-oxHDL on SMC migration using wound healing and transwell assays, proliferation using MTT and BrdU assays, and apoptosis using Annexin-V assay in vitro, as well as on atherosclerotic plaque stability in vivo using a coratid artery collar implantation mice model. RESULTS: Our results showed that native HDL promoted SMC proliferation and migration, whereas NO2-oxHDL and Cl-oxHDL inhibited SMC migration and reduced capacity of stimulating SMC proliferation as well as migration, respectively. OxHDL had no significant influence on SMC apoptosis. In addition, we found that ERK1/2-phosphorylation was significantly lower when SMCs were incubated with NO2-oxHDL and Cl-oxHDL. Furthermore, transwell experiments showed that differences between native HDL, NO2-oxHDL and Cl-oxHDL was abolished after PD98059 (MAPK kinase inhibitor) treatment. In aortic SMCs from scavenger receptor BI (SR-BI) deficient mice, differences between migration of native HDL, NO2-oxHDL and Cl-oxHDL treated SMCs vanished, indicating SR-BI's possible role in HDL-associated SMC migration. Importantly, NO2-oxHDL and Cl-oxHDL induced neointima formation and reduced SMC positive staining cells in atherosclerotic plaque, resulting in elevated vulnerable index of atherosclerotic plaque. CONCLUSION: These findings implicate MPO-catalyzed oxidization of HDL may contribute to atherosclerotic plaque instability by inhibiting SMC proliferation and migration through MAPK-ERK pathway which was dependent on SR-BI.

Ischemic preconditioning inhibits mitochondrial permeability transition pore opening through the PTEN/PDE4 signaling pathway.

OBJECTIVES: Ischemic preconditioning (IPC) induces cardioprotection against ischemia-reperfusion (IR) injury by inhibiting the mitochondrial permeability transition pore (mPTP). Here, we tested the hypothesis that IPC-induced cardioprotection is mediated by the phosphatase PTEN and PDE4 (phosphodiesterase 4). METHODS: Isolated hearts from wild-type mice (WT, n = 110) and myocyte-specific PTEN-knockout mice (PKO, n = 94) were exposed to IPC or control conditions followed by IR. Subcellular fractionation was performed by sucrose gradient ultracentrifugation. RESULTS: IPC limited myocardial infarct size (IS) in WT mice. The PDE4 inhibitor rolipram abolished the protective effect of IPC. However, small IS was found in PKO hearts after IR, and IPC did not decrease IS but enlarged it in PKO hearts. IPC promoted PDE4D localization to caveolin-3-enriched fractions in WT mice by increasing Akt levels at the caveolae. In PKO hearts, basal PDE4D levels were elevated at the caveolae, and IPC decreased PDE4D levels. Consistent with the subcellular PDE4D protein levels and its activity, elevation in intracellular Ca(2+) levels in the ischemic heart and opening of mPTP after IR were inhibited by IPC in WT mice, but not by IPC in PKO mice. CONCLUSIONS: IPC inhibits mPTP opening by regulating the PTEN/PDE4 signaling pathway.

Quantitative analysis of molecular transport in the extracellular space using physics-informed neural network.

The brain extracellular space (ECS), an irregular, extremely tortuous nanoscale space located between cells or between cells and blood vessels, is crucial for nerve cell survival. It plays a pivotal role in high-level brain functions such as memory, emotion, and sensation. However, the specific form of molecular transport within the ECS remain elusive. To address this challenge, this paper proposes a novel approach to quantitatively analyze the molecular transport within the ECS by solving an inverse problem derived from the advection-diffusion equation (ADE) using a physics-informed neural network (PINN). PINN provides a streamlined solution to the ADE without the need for intricate mathematical formulations or grid settings. Additionally, the optimization of PINN facilitates the automatic computation of the diffusion coefficient governing long-term molecule transport and the velocity of molecules driven by advection. Consequently, the proposed method allows for the quantitative analysis and identification of the specific pattern of molecular transport within the ECS through the calculation of the Péclet number. Experimental validation on two datasets of magnetic resonance images (MRIs) captured at different time points showcases the effectiveness of the proposed method. Notably, our simulations reveal identical molecular transport patterns between datasets representing rats with tracer injected into the same brain region. These findings highlight the potential of PINN as a promising tool for comprehensively exploring molecular transport within the ECS.

Quantification of functional hemodynamics in aortic valve disease using cardiac computed tomography angiography.

BACKGROUND AND OBJECTIVE: Cardiac computed tomography angiography (CTA) is the preferred modality for preoperative planning in aortic valve stenosis. However, it cannot provide essential functional hemodynamic data, specifically the mean transvalvular pressure gradient (MPG). This study aims to introduce a computational fluid dynamics (CFD) approach for MPG quantification using cardiac CTA, enhancing its diagnostic value. METHODS: Twenty patients underwent echocardiography, cardiac CTA, and invasive catheterization for pressure measurements. Cardiac CTA employed retrospective electrocardiographic gating to capture multi-phase data throughout the cardiac cycle. We segmented the region of interest based on mid-systolic phase cardiac CTA images. Then, we computed the average flow velocity into the aorta as the inlet boundary condition, using variations in end-diastolic and end-systolic left ventricular volume. Finally, we conducted CFD simulations using a steady-state model to obtain pressure distribution within the computational domain, allowing for the derivation of MPG. RESULTS: The mean value of MPG, measured via invasive catheterization (MPGInv), echocardiography (MPGEcho), and cardiac CTA (MPGCT), were 51.3 ± 28.4 mmHg, 44.8 ± 19.5 mmHg, and 55.8 ± 25.6 mmHg, respectively. In comparison to MPGInv, MPGCT exhibited a higher correlation of 0.91, surpassing that of MPGEcho, which was 0.82. Moreover, the limits of agreement for MPGCT ranged from -27.7 to 18.7, outperforming MPGEcho, which ranged from -40.1 to 18.0. CONCLUSIONS: The proposed method based on cardiac CTA enables the evaluation of MPG for aortic valve stenosis patients. In future clinical practice, a single cardiac CTA examination can comprehensively assess both the anatomical and functional hemodynamic aspects of aortic valve disease.

The NO-cGMP-PKG Axis in HFpEF: From Pathological Mechanisms to Potential Therapies.

Heart failure with preserved ejection fraction (HFpEF) accounts for almost half of all heart failure (HF) cases worldwide. Unfortunately, its incidence is expected to continue to rise, and effective therapy to improve clinical outcomes is lacking. Numerous efforts currently directed towards the pathophysiology of human HFpEF are uncovering signal transduction pathways and novel therapeutic targets. The nitric oxide-cyclic guanosine phosphate-protein kinase G (NO-cGMP-PKG) axis has been described as an important regulator of cardiac function. Suppression of the NO-cGMP-PKG signalling pathway is involved in the progression of HFpEF. Therefore, the NO-cGMP-PKG signalling pathway is a potential therapeutic target for HFpEF. In this review, we aim to explore the mechanism of NO-cGMP-PKG in the progression of HFpEF and to summarize potential therapeutic drugs that target this signalling pathway.

Fatty acid ß-oxidation and mitochondrial fusion are involved in cardiac microvascular endothelial cell protection induced by glucagon receptor antagonism in diabetic mice.

INTRODUCTION: The role of cardiac microvascular endothelial cells (CMECs) in diabetic cardiomyopathy is not fully understood. We aimed to investigate whether a glucagon receptor (GCGR) monoclonal antibody (mAb) ameliorated diabetic cardiomyopathy and clarify whether and how CMECs participated in the process. RESEARCH DESIGN AND METHODS: The db/db mice were treated with GCGR mAb or immunoglobulin G (as control) for 4 weeks. Echocardiography was performed to evaluate cardiac function. Immunofluorescent staining was used to determine microvascular density. The proteomic signature in isolated primary CMECs was analyzed by using tandem mass tag-based quantitative proteomic analysis. Some target proteins were verified by using western blot. RESULTS: Compared with db/m mice, cardiac microvascular density and left ventricular diastolic function were significantly reduced in db/db mice, and this reduction was attenuated by GCGR mAb treatment. A total of 199 differentially expressed proteins were upregulated in db/db mice versus db/m mice and downregulated in GCGR mAb-treated db/db mice versus db/db mice. The enrichment analysis demonstrated that fatty acid ß-oxidation and mitochondrial fusion were the key pathways. The changes of the related proteins carnitine palmitoyltransferase 1B, optic atrophy type 1, and mitofusin-1 were further verified by using western blot. The levels of these three proteins were upregulated in db/db mice, whereas this upregulation was attenuated by GCGR mAb treatment. CONCLUSION: GCGR antagonism has a protective effect on CMECs and cardiac diastolic function in diabetic mice, and this beneficial effect may be mediated via inhibiting fatty acid ß-oxidation and mitochondrial fusion in CMECs.

Development and Validation of Predictive Model-HASBLAD Score-For Major Adverse Cardiovascular Events During Perioperative Period of Non-cardiac Surgery: A Single Center Experience in China.

Background: Major adverse cardiovascular events (MACEs) represent a significant reason of morbidity and mortality in non-cardiac surgery during perioperative period. The prevention of perioperative MACEs has always been one of the hotspots in the research field. Current existing models have not been validated in Chinese population, and have become increasingly unable to adapt to current clinical needs. Objectives: To establish and validate several simple bedside tools for predicting MACEs during perioperative period of non-cardiac surgery in Chinese hospitalized patients. Design: We used a nested case-control study to establish our prediction models. A nomogram along with a risk score were developed using logistic regression analysis. An internal cohort was used to evaluate the performance of discrimination and calibration of these predictive models including the revised cardiac risk index (RCRI) score recommended by current guidelines. Setting: Peking University Third Hospital between January 2010 and December 2020. Patients: Two hundred and fifty three patients with MACEs and 1,012 patients without were included in the training set from January 2010 to December 2019 while 38,897 patients were included in the validation set from January 2020 and December 2020, of whom 112 patients had MACEs. Main Outcome Measures: The MACEs included the composite outcomes of cardiac death, non-fatal myocardial infarction, non-fatal congestive cardiac failure or hemodynamically significant ventricular arrhythmia, and Takotsubo cardiomyopathy. Results: Seven predictors, including Hemoglobin, CARDIAC diseases, Aspartate aminotransferase (AST), high Blood pressure, Leukocyte count, general Anesthesia, and Diabetes mellitus (HASBLAD), were selected in the final model. The nomogram and HASBLAD score all achieved satisfactory prediction performance in the training set (C statistic, 0.781 vs. 0.768) and the validation set (C statistic, 0.865 vs. 0.843). Good calibration was observed for the probability of MACEs in the training set and the validation set. The two predictive models both had excellent discrimination that performed better than RCRI in the validation set (C statistic, 0.660, P < 0.05 vs. nomogram and HASBLAD score). Conclusion: The nomogram and HASBLAD score could be useful bedside tools for predicting perioperative MACEs of non-cardiac surgery in Chinese hospitalized patients.

Peri-operative Takotsubo syndrome after non-cardiac surgery: a retrospective nested case-control study.

AIMS: Takotsubo syndrome (TTS) is an acute reversible cardiac dysfunction that may occur during the peri-operative period and among patients with serious illness. We aimed to evaluate the clinical characteristics, peri-operative management, and prognosis of peri-operative TTS (pTTS) and explore the factors associated with pTTS. METHODS: We conducted a retrospective nested case-control study using the database of patients who underwent in-hospital non-cardiac surgeries between January 2017 and December 2020 in Peking University Third hospital. Cases were adult patients diagnosed TTS at discharge who were matched with four controls based on operative types. Multivariable conditional logistic regression was used to identified the factors associated with pTTS. The area under the curve (AUC) was used to evaluate the diagnostic efficacy. RESULTS: Among the 128 536 patients underwent non-cardiac surgery, 20 patients with pTTS and 80 patients without were enrolled in this study. The incidence of pTTS was about 0.016% in our centre. The median age of patients with pTTS was 52.5 (38.25, 76.25) years, although 90% of them were female. Fifty per cent (9 cases) of female patients were pre-menopausal. Caesarean section has the highest proportion of pTTS (30% of the pTTS cases) with the incidence of caesarean section-related pTTS of 0.06% in our centre. A high prevalence of non-apical ballooning pattern of regional wall motion abnormality (seven cases, 35%) and a high mortality (two cases, 10%) were observed. Left ventricular ejection fraction (LVEF) of patients with pTTS was significantly decreased (41.7 ± 8.8%). In the acute phase, supportive treatments aiming to reduce life-threatening complications were main treatment strategies. After receiving systematic treatment, significant improvements were observed in LVEF (63.1 ± 13.5%), with median recovery time of LVEF of 7.48 days. Leucocyte count [odds ratio (OR): 4.59; 95% confidence interval (CI): 1.10-19.15], haemoglobin (HGB) (OR: 10.52; 95% CI: 1.04-106.36), and the revised cardiac risk index (RCRI) score (OR: 6.30; 95% CI: 1.05-37.88) were the factors significantly associated with pTTS. The RCRI score performed poorly in the prediction of pTTS (AUC: 0.630; 95% CI: 0.525-0.735). After adding leucocyte count and HGB into the RCRI score, the AUC was significantly improved (AUC: 0.768; 95% CI: 0.671-0.865; P = 0.001). CONCLUSIONS: Patients with pTTS have some differences compared with common TTS, including higher proportion of pre-menopausal female, higher prevalence during caesarean section, higher prevalence of non-apical ballooning pattern of regional wall motion abnormality, and higher mortality. The RCRI score performed poorly in the evaluation of pTTS. Adding HGB and leucocyte count into the RCRI score could significantly improve its predictive performance.

Short-term exposure to traffic-related air pollution and STEMI events: Insights into STEMI onset and related cardiac impairment.

AIMS: Evidence on the impacts of traffic-related air pollution (TRAP) on ST-segment elevation myocardial infarction (STEMI) events is limited. We aimed to assess the acute effects of TRAP exposure on the clinical onset of STEMI and related cardiac impairments. METHODS AND RESULTS: We recruited patients who were admitted for STEMI and underwent primary percutaneous coronary intervention at Peking University Third Hospital between 2014 and 2020. Indicators relevant to cardiac impairments were measured. Concomitantly, hourly concentrations of traffic pollutants were monitored throughout the study period, including fine particulate matter, black carbon (BC), particles in size ranges of 5-560 nm, oxides of nitrogen (NOX), nitrogen dioxide, and carbon monoxide. The mean (SD) age of participants was 62.4 (12.5) years. Daily average (range) concentrations of ambient BC and NOX were 3.9 (0.1-25.0) µg/m3 and 90.8 (16.6-371.7) µg/m3. Significant increases in STEMI risks of 5.9% (95% CI: 0.1, 12.0) to 21.9% (95% CI: 6.0, 40.2) were associated with interquartile range increases in exposure to TRAP within a few hours. These changes were accompanied by significant elevations in cardiac troponin T levels of 6.9% (95% CI: 0.2, 14.1) to 41.7% (95% CI: 21.2, 65.6), as well as reductions in left ventricular ejection fraction of 1.5% (95% CI: 0.1, 2.9) to 3.7% (95% CI: 0.8, 6.4). Furthermore, the associations were attenuated in participants living in areas with higher residential greenness levels. CONCLUSIONS: Our findings extend current understanding that short-term exposure to higher levels of traffic pollution was associated with increased STEMI risks and exacerbated cardiac impairments, and provide evidence on traffic pollution control priority for protecting vulnerable populations who are at greater risks of cardiovascular events.

Ischemic preconditioning attenuates mitochondrial localization of PTEN induced by ischemia-reperfusion.

Although the induction of myocyte apoptosis by ischemia-reperfusion (I/R) is attenuated by ischemic preconditioning (IPC), the underlying mechanism is not fully understood. Phosphatase and tensin homologs deleted on chromosome 10 (PTEN) promotes apoptosis through Akt-dependent and -independent mechanisms. We tested the hypothesis that IPC attenuates the mitochondrial localization of PTEN in the myocardium induced by I/R. Isolated hearts from wild-type mice were exposed to IPC or normal perfusion followed by 30 min of ischemia and reperfusion. IPC attenuated myocardial infarct size and apoptosis after I/R. Heart fractionation showed that mitochondrial PTEN and Bax protein levels and the physical association between them were increased by 30 min of I/R and that IPC attenuated all of these effects of I/R. Muscle-specific PTEN knockout decreased mitochondrial Bax protein levels in the reperfused myocardium and increased cell survival. To determine whether PTEN relocalization to mitochondria was influenced by I/R-induced production of ROS, hearts were perfused with N-acetylcysteine (NAC) to scavenge ROS or H(2)O(2) to mimic I/R-induced ROS. Mitochondrial PTEN protein levels were decreased by NAC and increased by H(2)O(2). PTEN protein overexpression was generated in mouse hearts by adenoviral gene transfer. PTEN overexpression increased mitochondrial PTEN and Bax protein levels and ROS production, whereas muscle-specific PTEN knockout produced the opposite effects. In conclusion, myocardial I/R causes PTEN localization to the mitochondria, related to the generation of ROS; IPC attenuates the mitochondrial localization of PTEN after I/R, potentially inhibiting the translocation of Bax to the mitochondria and resulting in improved cell viability.

Refining age stratum of the C2HEST score for predicting incident atrial fibrillation in a hospital-based Chinese population.

BACKGROUND: The C2HEST score (C2: coronary artery disease [CAD] / chronic obstructive pulmonary disease [COPD] (1 point each); H: Hypertension; E: Elderly (Age≥75, doubled); S: Systolic heart failure (doubled); T: Thyroid disease (hyperthyroidism)) has been validated to predict incident atrial fibrillation (AF). Its performance in the hospital-based Chinese population has never been evaluated. METHODS: Risk factors for incident AF were investigated in a hospital-based population. Comparison of the C2HEST score and other clinical scores with the capacity of predicting incident AF was conducted using area under the curves (AUC), net reclassification index (NRI), integrated discriminative improvement (IDI), and decision curve analysis (DCA). An age-stratified criterion was used to refine the C2HEST score to form a modified C2HEST score (mC2HEST). The performance of the mC2HEST score was also evaluated. RESULTS: A total of 23,523 patients entered the study with 520 developed AF during 2.84 ± 3.56 years of follow-up. Risk factors for incident AF included age, male sex, hypertension, CAD, COPD, previous ischemic stroke, hyperthyroidism, and heart failure. Age ≥65 years has significantly increased the risk of AF, which was considered as the age cutoff for a modified C2HEST score (mC2HEST). The risk of AF increased by 89% per one-point increase of the mC2HEST score. The mC2HEST score showed better predictive performance (AUC of 0.809) compared with the original C2HEST (AUC of 0.752), CHA2DS2-VASc (0.756), HATCH (0.722), and HAVOC (0.758) scores, also as estimated by IDI, NRI and DCA. Among those enrolled after 2012, the mC2HEST score had numerically higher AUC (0.849) compared with the C2HEST score (0.826) and the other scores. CONCLUSION: In a hospital-based Chinese population, by refining the age strata of the original C2HEST score, the mC2HEST score had significantly increased predictive accuracy and discriminative capability for incident AF. The clinical benefits of the application of novel mC2HEST score needs further validation in multiple settings.

Comparison of intraosseous access and central venous catheterization in Chinese adult emergency patients: A prospective, multicenter, and randomized study.

BACKGROUND: It is challenging to establish peripheral intravenous access in adult critically patients. This study aims to compare the success rate of the first attempt, procedure time, operator satisfaction with the used devices, pain score, and complications between intraosseous (IO) access and central venous catheterization (CVC) in critically ill Chinese patients. METHODS: In this prospective clustered randomized controlled trial, eight hospitals were randomly divided into either the IO group or the CVC group. Patients who needed emergency vascular access were included. From April 1, 2017 to December 31, 2018, each center included 12 patients. We recorded the data mentioned above. RESULTS: A total of 96 patients were enrolled in the study. There were no statistically significant differences between the two groups regarding sex, age, body mass index, or operator satisfaction with the used devices. The success rates of the first attempt and the procedure time were statistically significant between the IO group and the CVC group (91.7% vs. 50.0%, P<0.001; 52.0 seconds vs. 900.0 seconds, P<0.001). During the study, 32 patients were conscious. There was no statistically significant difference between the two groups regarding the pain score associated with insertion. There were statistically significant differences between the two groups regarding the pain score associated with IO or CVC infusion (1.5 vs. 0.0, P=0.044). Complications were not observed in the two groups. CONCLUSIONS: IO access is a safe, rapid, and effective technique for gaining vascular access in critically ill adults with inaccessible peripheral veins in the emergency departments.

Evidence for a role of immunoproteasomes in regulating cardiac muscle mass in diabetic mice.

The ubiquitin-proteasome system plays an important role in regulating muscle mass. Inducible immunoproteasome subunits LMP-2 and LMP-7 are constitutively expressed in the heart; however, their regulation and functions are poorly understood. We here investigated the hypothesis that immunoproteasomes regulate cardiac muscle mass in diabetic mice. Type 1 diabetes was induced in wildtype mice by streptozotocin. After hyperglycemia developed, insulin and the proteasome inhibitor epoxomicin were used to treat diabetic mice for 6weeks. Isolated mouse hearts were perfused with control or high glucose solution. Catalytic proteasome beta-subunits and proteolytic activities were analyzed in the heart by immunoblotting and fluorogenic peptide degradation assays, respectively. Insulin and epoxomicin blocked loss of heart weight and improved cardiac function in diabetic mice. LMP-7 and its corresponding chymotryptic-like proteasome activity were increased in diabetic hearts and high glucose-treated hearts. Myosin heavy chain protein was decreased in diabetic hearts, which was largely reversed by epoxomicin. High glucose decreased LMP-2 protein levels in perfused hearts. In diabetic hearts, LMP-2 expression was downregulated whereas expression of the phosphatase and tensin homologue deleted on chromosome ten (PTEN) and the muscle atrophy F-box were upregulated. Moreover, mice with muscle-specific knockout of PTEN gene demonstrated increased cardiac muscle mass, while mice with LMP-2 deficiency demonstrated PTEN accumulation, muscle mass loss, and contractile impairment in the heart. Therefore, we concluded that high glucose regulates immunoproteasome subunits and modifies proteasome activities in the heart, and that dysregulated immunoproteasome subunits may mediate loss of cardiac muscle mass in experimental diabetic mice.

A Non-Invasive Nanoprobe for In Vivo Photoacoustic Imaging of Vulnerable Atherosclerotic Plaque.

Vulnerable atherosclerotic (AS) plaque is the major cause of cardiovascular death. However, clinical methods cannot directly identify the vulnerable AS plaque at molecule level. Herein, osteopontin antibody (OPN Ab) and NIR fluorescence molecules of ICG co-assembled Ti3 C2 nanosheets are reported as an advanced nanoprobe (OPN Ab/Ti3 C2 /ICG) with enhanced photoacoustic (PA) performance for direct and non-invasive in vivo visual imaging of vulnerable AS plaque. The designed OPN Ab/Ti3 C2 /ICG nanoprobes successfully realize obvious NIR fluorescence imaging toward foam cells as well as the vulnerable AS plaque slices. After intravenous injection of OPN Ab/Ti3 C2 /ICG nanoprobes into AS model mice, in vivo imaging results show a significantly enhanced PA signal in the aortic arch accumulated with vulnerable plaque, well indicating the remarkable feasibility of OPN Ab/Ti3 C2 /ICG nanoprobes to distinguish the vulnerable AS plaque. The proposed OPN Ab/Ti3 C2 /ICG nanoprobes not only overcome the clinical difficulty to differentiate vulnerable plaque, but also achieve the non-invasively specific in vivo imaging of vulnerable AS plaque at molecule level, greatly promoting the innovation of cardiovascular diagnosis technology.

Connexin43 and Myocardial Ischemia-Reperfusion Injury.

BACKGROUND: Recently, the treatment and prevention of ischemic cardiomyopathy is one of the emerging research topics in the cardiovascular field. Gap junction is the basic structure of cardiac electrophysiology. Connexin is the basic unit of gap junctions. Connexin43(CX43) is the most abundant member of Cx family in the heart, the normal expression of Cx43 is important for heart development, electrically coupled cardiomyocytes activities and coordination of myocardial function. The connection between Cx43 and myocardial ischemia/reperfusion or reperfusion injury has become the focus of current research. METHODS: We undertook a structured search of bibliographic database for peer-reviewed research literature using a focused review question and inclusion/exclusion criteria. The quality of retrieved papers was appraised using standard tools. The characteristics of screened papers were described, and a deductive qualitative content analysis methodology was applied to analyze the interventions and findings of included studies using a conceptual framework. RESULTS: Twenty-one papers were included in the review, eight papers outlined the relationship of Cx43 and reperfusion arrhythmias. Eight papers pointed out the effect on the infarct size of Cx43. CONCLUSION: The findings of this review confirm that Cx43 is the most abundant member of Cx family in the heart and is vital for myocardial protection during ischemia/reperfusion process and for ischemia/reperfusion injury. Many of its mechanism are still not very clear and require future research in the future.

[Adhesion between monocytes and vascular smooth muscle cells induced by integrin beta1-mediated platelet-derived growth factor].

OBJECTIVE: To investigate the effects of platelet-derived growth factor (PDGF)-BB on the vascular smooth muscle cell (VSMC)-monocyte interaction and the mechanism thereof. METHODS: Rat aortic VSMC were pretreated with PDGF-BB of the concentrations of 0, 2.5, 5, 10, and 20 ng/ml for 8 hours and then co-incubated with human monocytes of the line THP-1 labeled with PKH26, a cellular membrane fluorescent marker, i.e., to be subjected to binding assay to observe the dose-effect relationship. Other VSMC were co-cultured with PDGF of the concentration of 10 ng/ml for 1, 2, 4, 12, and 24 hours respectively and then interacted with PKH26-abeled THP-1 cells so as to observe the time-response relationship. Monoclonal antibody against integrin beta1 was co-cultured with VSMC for 30 min, and then PKH26-labeled THP-1 cells were added to block the effect of PDGF. After the incubation of THP-1 cells and VSMC, the amount of bound cells was counted using fluorescent phase-contrast microscopy. The effect of PDGF on the expression of integrin beta1 was detected by Western blotting. RESULTS: The amounts of THP-1 cells bound to VSMC pretreated with PDGF of the concentrations of 2.5, 5, 10, and 20 ng/ml respectively were 1.1, 2.1, 3.1, and 4.4 times that of the untreated cells. Incubated with 10 ng/ml PDGF for 0-18 h, the adhesion rate between the VSMC and THP-1 cells increased time-1dependently. After the blocking by the antibody against integrin beta1, the adhesion rate between the VSMC and THP-1 cells decreased from (25.4+/-11.4)% to (9.2+/-4.1)% (P<0.01). Western blotting showed that the level of integrin beta1 of the VSMC treated by 10 ng/ml PDGF increased since 4 h after the treatment, peaked 8 h later, and then decreased gradually. CONCLUSION: PDGF-BB can induce the binding of monocytes to VSMC via the integrin-beta1 signaling pathway. The effect may therefore facilitate the progression of atherosclerosis by augmenting the VSMC-monocyte adhesive interaction.

Antiproteinase 3 Positive Eosinophilic Granulomatosis with Polyangiitis Presenting with Heart Failure and Intraventricular Thrombosis.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare systemic vasculitis commonly with cardiac complications. We describe a case of anti-PR3 ANCA-positive EGPA complicated by congestive heart failure and intraventricular thrombosis. Interestingly, the thrombus was resolved rapidly with steroid and cyclophosphamide in the setting of interrupted anticoagulation. To the best of our knowledge, we report the first case of anti-PR3 positive EGPA with extensive cardiac involvement. Our patient had overlapping features with previously studied ANCA-positive and ANCA-negative EGPA cases. We also hypothesize that the thrombogenic potential of eosinophils may play a central role in thrombogenesis in EGPA and aggressive immunosuppressive therapy remains the cornerstone of treatment, and the addition of anticoagulation therapy in the setting of thrombus formation and also very high risk of bleeding needs to be considered cautiously.

[Effects of tissue inhibitor of matrix metalloproteinases-4 on the activities of matrix metalloproteinases and collagen of artery: experiment with rats].

OBJECTIVE: To investigate the effects of tissue inhibitor of matrix metalloproteinases-4 (TIMP-4) on the activities of matrix metalloproteinases (MMPs) and the collagen deposition. METHODS: Vascular smooth muscle cells (VSMCs) of rat thoracic aorta were cultured and divided into 3 groups: 2 groups to be transfected with adenovirus vector containing green fluorescence protein (AdGFP) or adenovirus vector containing TIMP-4 (AdTIMP-4), and one group un-transfected. Zymography and reverse zymography were used to detect the activities of MMP-2, MMP-9 and TIMP-4 in the supernatants. Male Wistar rats underwent balloon injury of common carotid artery and then divided into 3 groups: pure injury group, AdGFP transfection group, and AdTIMP-4. transfection group. Four and 28 days later 3 and 6 rats were killed in each group respectively to undergo microscopy and examination of the activities of MMP-2, MMP-9, and TIMP-4, and collagen quantity. RESULTS: The MMP-2 activity in the VSMC culture fluid supernatant of the AdTIMP-4 group was decreased dose-dependently, however, the activity of MMP-9 did not changed significantly among the 3 groups. Bands of activated MMP-2 and MMP-9 could not be examined in the normal vessel tissues. Four hours after the injury, the activity of MMP-2 was significantly increased in the pure injury group and AdGFP group, however, was significantly decreased in the AdTIMP-4 group. Four days later no MMP activity could be detected in either group. The neoformation of tunica intima was inhibited by 66% in the AdTIMP-4 group, The collagen quantity per vessel cell was 12.1 +/- 1.0 in the AdGFP group, not significantly different from that of in the AdTIMP-4 group (11.9 +/- 1, P > 0.05), and the collagen quantity per tunica adventitia cell in the AdTIMP-4 group was 118 +/- 13, not significantly different from that of the pure injury group (135 +/- 11, P > 0.05). CONCLUSION: The regulation of MMP/TIMP balance by TIMP-4 may control the metabolism of collagen and play an important role in the vascular repair process.

Relationship between metabolites of arachidonic acid and prognosis in patients with acute coronary syndrome.

OBJECTIVE: To investigate the correlation of arachidonic acid (ARA) metabolites and prognosis in ACS patients. METHODS AND RESULTS: This is a mono-center retrospective nested case-control study. We followed up 470 ACS patients, of whom 39 patients had MACE in a mean follow up time of 1037days (identified as MACE group). Another 39 clinically matched patients without MACE were selected from the 470 ACS patients (Non-MACE group). Thirty-nine subjects without Coronary Heart Disease were enrolled as Control group. Metabolites of ARA were determined by LC-MS/MS. We found that plasma levels of LTB4, 8-HETE, 11-HETE, 12-HETE, and 15-HETE were significantly increased in MACE and Non-MACE groups, 5-HETE and 9-HETE were significantly increased in MACE group comparing with Control group (P<0.05). Importantly, plasma level of 19-HETE in MACE group was significantly lower than Non-MACE and Control groups. 19-HETE significantly correlated with the prognosis of ACS after adjustment for clinical characteristics (HR=0.103, 95% C.I.: 0.014-0.766). The AUC for ROC curve of 19-HETE in predicting MACE was 0.637 (P<0.05). Survival analysis showed that ACS patients with 19-HETE levels higher than 0.13ng/ml tend to have better prognosis than those lower than 0.13ng/ml (P<0.05). GRACE score and serum Fib levels were also significantly correlated with MACE. 20-HETE level was found significantly higher in STEMI group comparing with NSTE-ACS group (P<0.05). CONCLUSION: Plasma arachidonic acid metabolites may act as prognostic markers for ACS patients.