CXCL16 Promotes Ly6Chigh Monocyte Infiltration and Impairs Heart Function after Acute Myocardial Infarction.

High CXCL16 levels during acute cardiovascular events increase long-term mortality. However, the mechanistic role of CXCL16 in myocardial infarction (MI) is unknown. Here we investigated the role of CXCL16 in mice with MI injury. CXCL16 deficiency increased the survival of mice after MI injury, and inactivation of CXCL16 resulted in improved cardiac function and decreased infarct size. Hearts from CXCL16 inactive mice exhibited decreased infiltration of Ly6Chigh monocytes. In addition, CXCL16 promoted the macrophage expression of CCL4 and CCL5. Both CCL4 and CCL5 stimulated Ly6Chigh monocyte migration, and CXCL16 inactive mice had a reduced expression of CCL4 and CCL5 in the heart after MI. Mechanistically, CXCL16 promoted CCL4 and CCL5 expression by activating the NF-κB and p38 MAPK signaling pathways. Anti-CXCL16 neutralizing Ab administration inhibited Ly6Chigh monocyte infiltration and improved cardiac function after MI. Additionally, anti-CCL4 and anti-CCL5 neutralizing Ab administration inhibited Ly6Chigh monocyte infiltration and improved cardiac function after MI. Thus, CXCL16 aggravated cardiac injury in MI mice by facilitating Ly6Chigh monocyte infiltration.

Polyhalogenation-Facilitated Spirolactonization at the meta-Position of Phenols.

A novel dearomative spirolactonization/polyhalogenation of phenols that employs hypervalent iodine PhICl2 (iodobenzene dichloride) as both an oxidant and chlorine source with an indispensable base, or only using NBS (N-bromosuccinimide) without any additives, is presented. Halide participations are a vital factor in the cascade reaction of 3'-hydroxy-[1,1'-biphenyl]-2-carboxylic acids with good selectivities and reactivities and induced the rapid constructions of multiple C-halogen bonds and directional C═O bonds in a one-step operation under mild conditions. In gaining a good understanding of the mechanism, the increase in number of bromine atoms was inferred rationally from the spirolactonization process, assisted by DFT calculations and high-resolution mass spectrometry. Mechanistic experiments suggest that the formation of a stable carbocation intermediate plays a great role in the migration of oxygen to spirolactonization.

Electrochemically Oxidative Phosphating of Aldehydes and Ketones.

Disclosed herein is the first protocol for the electrochemically oxidative phosphating of aldehydes and ketones to generate α-hydroxyphosphine oxides with diphenylphosphine as the phosphine source. Various phosphating products containing P-C bonds are basically assembled in modest to excellent yields. This electrochemical phosphating was achieved by utilizing a simple undivided cell with foam nickel electrodes at room temperature without the addition of any oxidant or metal catalyst. The prepared α-hydroxyphosphine oxides possess potential application in pharmacological research.

Facile fabrication of highly exothermic CuO@Al nanothermites via self-assembly approach.

CuO@Al nanothermites with Al shell and CuO core were successfully fabricated via a simple self-assembly route. The composition and morphology of CuO@Al nanothermites were analyzed by x-ray diffraction and field-emission scanning electron microscopy in detail. When the equivalence ratio was 1.0, the heat output of CuO@Al nanothermites reached 1252 J g-1, which was significantly larger than that of the Al/CuO prepared by ultrasonic mixing. The greatest heat output of CuO@Al nanothermites reached 1860 J g-1, demonstrating outstanding exothermic properties, which ascribed to their unique core-shell structure. This study provides a new strategy about the design and advancement of highly exothermic nanothermites.

The Complement C3a-C3aR Axis Promotes Development of Thoracic Aortic Dissection via Regulation of MMP2 Expression.

Thoracic aortic dissection (TAD), once ruptured, is devastating to patients, and no effective pharmaceutical therapy is available. Anaphylatoxins released by complement activation are involved in a variety of diseases. However, the role of the complement system in TAD is unknown. We found that plasma levels of C3a, C4a, and C5a were significantly increased in patients with TAD. Elevated circulating C3a levels were also detected in the developmental process of mouse TAD, which was induced by ß-aminopropionitrile monofumarate (BAPN) treatment, with enhanced expression of C1q and properdin in mouse dissected aortas. These findings indicated activation of classical and alternative complement pathways. Further, expression of C3aR was obviously increased in smooth muscle cells of human and mouse dissected aortas, and knockout of C3aR notably inhibited BAPN-induced formation and rupture of TAD in mice. C3aR antagonist administered pre- and post-BAPN treatment attenuated the development of TAD. We found that C3aR knockout decreased matrix metalloproteinase 2 (MMP2) expression in BAPN-treated mice. Additionally, recombinant C3a stimulation enhanced MMP2 expression and activation in smooth muscle cells that were subjected to mechanical stretch. Finally, we generated MMP2-knockdown mice by in vivo MMP2 short hairpin RNA delivery using recombinant adeno-associated virus and found that MMP2 deficiency significantly reduced the formation of TAD. Therefore, our study suggests that the C3a-C3aR axis contributes to the development of TAD via regulation of MMP2 expression. Targeting the C3a-C3aR axis may represent a strategy for inhibiting the formation of TAD.

ER stress dependent microparticles derived from smooth muscle cells promote endothelial dysfunction during thoracic aortic aneurysm and dissection.

The degeneration of vascular smooth muscle cell(s) (SMC) is one of the key features of thoracic aortic aneurysm and dissection (TAAD). We and others have shown that elevated endoplasmic reticulum (ER) stress causes SMC loss and TAAD formation, however, the mechanism of how SMC dysfunction contributes to intimal damage, leading to TAAD, remains to be explored. In the present study, in vitro assay demonstrated that elevated mechanical stretch (18% elongation, 3600 cycles/h) stimulated the ER stress response and microparticle(s) (MP) production from both SMC and endothelial cell(s) (EC) in a time-dependent manner. Treatment of EC with isolated MP led to anoikis, which was determined by measuring the fluorescence of the ethidium homodimer (EthD-1) and Calcein AM cultured in hydrogel-coated plates and control plates. MP stimulation of EC also up-regulated the mRNA levels of inflammatory molecules (i.e. Vascular cellular adhesion molecular-1 (VCAM-1)), intercellular adhesion molecular-1 (ICAM-1), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6)). Use of an ER stress inhibitor or knockout of CHOP decreased mechanical stretch-induced MP production in SMC. In vivo, administration of an ER stress inhibitor or knockout of CHOP suppressed both apoptosis of EC and the infiltration of inflammatory cells. Moreover, TAAD formation was also suppressed by the administration of an ER stress inhibitor. In conclusion, our study demonstrates that elevated mechanical stretch induces MP formation in SMC leading to endothelial dysfunction, which is ER stress dependent. The inhibition of ER stress suppressed EC apoptosis, inflammation in the aorta, and TAAD development.

Influencing factors and improvement paths of manufacturing innovation performance: Configuration analysis based on TOE framework.

Innovation is the first driving force to lead development, how to improve manufacturing innovation performance has become a hot topic. Based on 47 listed companies in the computer, communication and other electronic equipment manufacturing industry in the A-share market, this paper adopted the Fuzzy set qualitative comparative analysis (fsQCA) to explore the influencing factors of technology, organization and environment on the innovation performance of manufacturing industry and the improvement path. The findings are as follows: (1) A single condition is not a necessary condition for high innovation performance in manufacturing industry, but government support plays a key role in improving innovation performance in manufacturing industry. (2) There are two improvement paths for high innovation performance in manufacturing industry, which are specifically explained as "technology-environment dual improvement path" and "technology-organization-environment collaborative improvement path". (3) The improvement of innovation performance in the manufacturing industry is the result of multiple factors, showing the characteristics of "all paths lead to the same destination". Different manufacturing enterprises have different paths to improve innovation performance based on their actual conditions. Based on these findings, this study may provide some implications for the effective improvement of manufacturing innovation performance.

Dual Loading Antiplatelet Therapy in Patients With Acute Coronary Syndrome and High Bleeding Risk Undergoing Percutaneous Coronary Intervention: Findings From the Improving Care for Cardiovascular Disease in China Project.

Objective: Loading dose of dual antiplatelet therapy (LD) is supported by the guidelines for patients with acute coronary syndrome (ACS). However, limited data is provided in the series of high bleeding risk (HBR) patients with ACS and percutaneous coronary intervention (PCI). Methods: Using data from the Improving Care for Cardiovascular Disease in China-Acute Coronary Syndrome registry, conducted between 2014 and 2019, we stratified all ACS patients with HBR and PCI according to LD used within 24 h of first medical contact or not. Inverse probability of treatment weighting (IPTW) and Cox proportional hazards model with hospital as random effect were used to analyze differences in in-hospital clinical outcomes: the primary efficacy endpoint was mortality, and the primary safety endpoint was bleeding. Results: Of 21,654 evaluable patients 14,322 (66.2%) were treated with LD, and were on average older, less likely to have comorbidities and higher hemoglobin, more often treated GPI and anticoagulant during hospitalization than those without LD. After IPTW adjustment for baseline differences, LD was associated with significantly increased risk of in-hospital mortality [1.89 vs. 1.02%; hazard ratio (HR): 1.71 (95% confidence interval 1.12, 2.42); p < 0.001] and in-hospital bleeding [3.89 vs. 3.3%; HR: 1.25 (1.03, 1.53); p = 0.03]. Conclusions: In ACS patients with HBR, LD was associated with an increased risk of in-hospital mortality and bleeding complications after PCI. Dedicated randomized trials with contemporary ACS management are needed to confirm these findings.

Secreted Frizzled-Related Protein 5 Protects Against Cardiac Rupture and Improves Cardiac Function Through Inhibiting Mitochondrial Dysfunction.

Background: Secreted frizzled-related protein 5 (Sfrp5) has been suggested to be a protective regulatory protein in coronary heart disease. However, the role of Sfrp5 in regulating ischemic injury and its consequences is not known. The aim of our study was to explore the effects of Sfrp5 on hearts after myocardial infarction (MI) and to investigate the underlying mechanisms. Methods and Results: We found that Sfrp5 was downregulated over time in the heart tissue of MI mice. To further elucidate the role of Sfrp5 during MI, we established a cardiac overexpression of an Sfrp5 mouse model using the cardiotropic adeno-associated virus serotype 9 (AAV9). Overexpression of Sfrp5 significantly reduced infarct size as demonstrated by a decrease in mortality owing to cardiac rupture. Moreover, cardiac overexpression of Sfrp5 increased left ventricular function and mitochondrial biogenesis, decreased cardiomyocyte apoptosis, suppressed inflammation reaction, inhibited oxidative stress, and ameliorated cardiac remodeling as demonstrated by left ventricular ejection fraction, mitochondrial morphology, heart weight, NADH oxidase activity levels, and myocardial fibrosis at 2 weeks post-MI. At the molecular level, overexpression of Sfrp5 significantly increased the expression of p-AMPKThr172 protein with higher expression of mitochondrial fusion protein (MFN1 and MFN2) and lower expression of mitochondrial fission protein (p-Drp1Ser616/Mid49/MFF/Fis-1). In isolated neonatal rat cardiac myocytes, Sfrp5 treatment attenuated hypoxia-induced mitochondrial dysfunction. Inhibition of AMPK activity with compound C abrogated this benefit. Conclusions: Sfrp5 overexpression inhibits ischemic injury, reduces risk of cardiac rupture, ameliorates post-MI remodeling, and decreases the progression to heart failure via disrupting mitochondrial dysfunction and partly through normalizing the AMPK activity.

Phosphodiesterase-5a Knock-out Suppresses Inflammation by Down-Regulating Adhesion Molecules in Cardiac Rupture Following Myocardial Infarction.

Cardiac rupture is a fatal complication of acute myocardial infarction (MI), associated with increased inflammation and damaged extracellular matrix. C57BL/6 J wild type (WT) and Pde5a knockout (Pde5a-/-) mice were selected to establish MI model. The rupture rate of Pde5a-/- mice was significantly reduced (P < 0.01) within 7 days post MI. The cardiac function of Pde5a-/- mice was better than WT mice both at day 3 and 7 post MI. Immunohistochemical staining and flow cytometry showed neutrophils and macrophages were decreased in Pde5a-/- mouse hearts. Inflammatory factors expression such as IL-1ß, IL-6, IL-8, Mcp-1, TNF-α significantly decreased in Pde5a-/- mice post MI. Moreover, western blot showed the inhibition of inflammatory response was accompanied by down-regulation of intercellular adhesion molecule-1(ICAM-1) and vascular cell adhesion molecule-1(VCAM-1) in Pde5a-/- mice. Knockout of Pde5a reduced inflammatory cells infiltration by down-regulating the expression of ICAM-1 and VCAM-1, and prevented early cardiac rupture after MI. All authors declare that they have no conflicts of interest. This article does not contain any studies with human participants performed by any of the authors. All applicable international, national, and institutional guidelines for the care and use of animals were followed.

TMEM43-S358L mutation enhances NF-κB-TGFß signal cascade in arrhythmogenic right ventricular dysplasia/cardiomyopathy.

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is a genetic cardiac muscle disease that accounts for approximately 30% sudden cardiac death in young adults. The Ser358Leu mutation of transmembrane protein 43 (TMEM43) was commonly identified in the patients of highly lethal and fully penetrant ARVD subtype, ARVD5. Here, we generated TMEM43 S358L mouse to explore the underlying mechanism. This mouse strain showed the classic pathologies of ARVD patients, including structural abnormalities and cardiac fibrofatty. TMEM43 S358L mutation led to hyper-activated nuclear factor κB (NF-κB) activation in heart tissues and primary cardiomyocyte cells. Importantly, this hyper activation of NF-κB directly drove the expression of pro-fibrotic gene, transforming growth factor beta (TGFß1), and enhanced downstream signal, indicating that TMEM43 S358L mutation up-regulates NF-κB-TGFß signal cascade during ARVD cardiac fibrosis. Our study partially reveals the regulatory mechanism of ARVD development.

Trimetazidine suppresses oxidative stress, inhibits MMP-2 and MMP-9 expression, and prevents cardiac rupture in mice with myocardial infarction.

BACKGROUND/AIMS: Cardiac rupture (CR) is a catastrophic complication of acute myocardial infarction (MI). At present, there are no effective pharmacological strategies for preventing post-MI rupture. Here we investigated the effect of trimetazidine (TMZ) on post-MI CR. METHODS: MI models were induced by left coronary artery ligation in male C57BL/6 mice. Animals allocated to the rupture incidence were closely monitored for 7 days; autopsy was performed once animals were found dead to determine the reason of death. Heart function was detected by echocardiography. Oxidative stress markers and matrix metalloproteinases (MMPs) were analyzed by Western Blotting. RESULTS: TMZ markedly reduced the post-MI CR incidence of mice. We found that the expression of metalloproteinase (MMP) -2 and MMP-9 in the TMZ-treated group was significantly lower than the saline-treated group. Further, TMZ markedly attenuated MI-induced oxidative stress. To investigate the mechanism of the effect of TMZ on CR, we pretreated H9c2 cells with H2 O2 and found that TMZ treatment markedly decreased H2 O2 -induced MMP-2 and MMP-9 expression. TMZ prevents CR through inhibition of oxidative stress, which is attributable to the down-regulation of MMP-2, MMP-9 expression. CONCLUSIONS: Our findings indicate that TMZ suppresses oxidative stress, inhibits MMP-2 and MMP-9 expression, and prevents CR in mice with MI.

Haplodeficiency of Ataxia Telangiectasia Mutated Accelerates Heart Failure After Myocardial Infarction.

BACKGROUND: Cell senescence is involved in the process of organ damage and repair; however, the underlying molecular mechanism needs to be further explored. METHODS AND RESULTS: Senescence-related genes (ie, p21, p53, and ataxia telangiectasia mutated [ATM]) were shown to be elevated after myocardial infarction (MI) in both mouse and human hearts. Ten- to 12-week-old male wild-type littermates (ATM+/+) and ATM heterozygous mice (ATM+/-) were subjected to MI. Cardiac echography showed that ATM haplodeficiency did not affect the survival rate but aggravated heart failure at day 28 post MI. Histologic analysis showed increased fibrosis in the noninfarct area of ATM+/- mice compared with that in ATM+/+ mice. Senescence-associated ß-galactosidase staining showed that the number of senescent fibroblasts was decreased when ATM was haplodeficient both in vivo and in vitro. Costaining of α-smooth muscle actin with p53 or p19 showed fewer senescent myofibroblasts in ATM+/- mouse hearts. Moreover, angiogenesis was also examined using the endothelial markers CD31 both at early (day 7) and late stages (day 28) after MI, and ATM haplodeficiency reduced angiogenesis after MI. Finally, cardiac fibroblasts were isolated from infarcted mouse heart and the medium were tested for its capacity of endothelial tubing formation, revealing that ATM haplodeficiency led to lower vascular endothelial growth factor production from cardiac fibroblast and reduced capacity of endothelial tube formation in vitro. CONCLUSIONS: The present study shows that ATM haplodeficiency decreases fibroblast senescence and vascular endothelial growth factor production and impaired angiogenesis in response to MI, leading to accelerated heart failure.

Characterization of Hemodynamics in Great Arteries of Wild-Type Mouse Using Computational Fluid Dynamics Based on Ultrasound Images.

Hemodynamic factors in cardiovascular system are hypothesized to play a significant role in causing structural heart development. It is thus important to improve our understanding of velocity characteristics and parameters. We present such a study on wild-type mouse to characterize the vessel geometry, flow pattern, and wall shear stress in great arteries. Microultrasound imaging for small animals was used to measure blood boundary and velocity of the great arteries. Subsequently, specimens' flow boundary conditions were used for 3-dimensional reconstructions of the great artery and aortic arch dimensions, and blood flow velocity data were input into subject-specific computational fluid dynamics for modeling hemodynamics. Measurement by microultrasound imaging showed that blood velocities in the great artery and aortic arch had strong correlations with vascular sizes, whereas blood pressure had a weak trend in relation to vascular size. Wall shear stress magnitude increased when closer to arterial branches and reduced proximally in the aortic root and distally in the descending aorta, and the parameters were related to the fluid mechanics in branches in some degree. We developed a method to investigate fluid mechanics in mouse arteries, using a combination of microultrasound and computational fluid dynamics, and demonstrated its ability to reveal detailed geometric, kinematic, and fluid mechanics parameters.

Deficiency of IL-12p35 improves cardiac repair after myocardial infarction by promoting angiogenesis.

AIMS: IL-12p35 is a pro-inflammatory cytokine that participates in a variety of inflammatory diseases. This study aimed to determine whether IL-12 regulates cardiac injury and repair following acute myocardial infarction (AMI) and investigate the underlying mechanisms. METHODS AND RESULTS: Mice with AMI showed a marked increase in IL-12p35 expression of ischaemic cardiac tissues. IL-12 was mainly produced by CD11b(+) monocytes. Cardiac functions were significantly improved in IL-12p35 knockout (p35-KO) mice compared with wild-type (WT) littermates in response to AMI. IL-12p35 deficiency attenuated the infarct scar and hypertrophy compared with WT mice. RNA transcriptome sequencing and quantitative RT-PCR analysis of CD11b(+) monocytes isolated from WT and p35-KO ischaemic hearts revealed a distinct transcriptional profile in p35-KO CD11b(+) monocytes, displaying pro-angiogenesis and anti-inflammation properties. Angiogenesis was enhanced in p35-KO mice with AMI and hindlimb ischaemia. Moreover, tube formation assay and Matrigel plug analysis demonstrated that IL-12 inhibition of angiogenesis was dependent on monocytes. IL-12p35 deficiency inhibited inflammation by reducing chemokine production and monocyte infiltration into the heart. Finally, administration of an IL-12p35-neutralizing antibody limited AMI-induced inflammatory cell infiltration into the heart and improved angiogenesis and cardiac function. CONCLUSIONS: Deficiency of IL-12p35 limited AMI-induced cardiac injury by promoting pro-angiogenesis and anti-inflammatory functions of monocytes.