CO2-Accelerated Carbonation Modification for Recycled Coarse Aggregate with Various Original Concrete Strengths and Coarse Aggregate Sizes.

The increasing demand for concrete reduces natural resources, such as sand and gravel, and also leads to a sharp increase in the amount of waste concrete produced. Due to the fact that the physical and mechanical properties of waste concrete made of recycled aggregates (RAs) differ greatly, it is difficult to use directly as a raw material for reinforced concrete (RC) components, which greatly restricts the popularization and application of RAs in actual projects. Utilizing the alkali aggregate properties of RAs to capture CO2 from industrial waste gases is an innovative way of enhancing their properties and promoting their application in real projects. However, the extent of the influence of original concrete strength (OCS) and coarse aggregate size (CAS) on the accelerated carbonation modification of RA is not clear, and a quantitative description is still required. For this purpose, accelerated carbonation tests on recycled coarse aggregate (RCA) samples under completely dry condition were carried out, and the variation laws for the physical property indicators of RCA samples before and after accelerated carbonation versus the OCS and CAS were revealed. Moreover, the influence degrees of the two factors, OCS and CAS, on the property enhancement of RCAs after accelerated carbonation were clarified, and the results of OCS and CAS corresponding to the best accelerated carbonation effects of RCAs were determined. By analyzing the micromorphology of RCA before and after accelerated carbonation, the reasons for property enhancement of RCAs with various OCSs and CASs under the best carbonation modifications were clarified. The findings will contribute to the development of basic theoretical research on accelerated carbonation modification of RA and have important scientific value.

Structural Characterization and Screening for Anti-inflammatory Activity of Polysaccharides with Different Molecular Weights from Astragali Radix.

Astragali Radix polysaccharides (APSs) exhibit a broad spectrum of biological activity, which is mainly related to immune regulation. At present, most available studies focus on total APSs or a certain component of APSs. However, systematic structural study and screening for the anti-inflammatory activity of polysaccharides with different molecular weights (MW) have yet to be conducted. In this study, lipopolysaccharide (LPS)-induced RAW264.7 macrophages were used as a model to investigate the anti-inflammatory activity of APSs and its fractions. The results revealed that fraction APS-I had better anti-inflammatory effects than APS-II. After APS-I was hydrolyzed by trifluoroacetic acid (TFA), the resulting degradation products oligosaccharides were fully methylated. These derivatized oligosaccharides were further analyzed by MALDI-TOF-MS and UPLC-Q-Exactive-MS/MS. The results showed that APS-I was a hetero-polysaccharide with a molecular weight of about 2.0×106 Da, mainly consisting of glucose (46.8 %) and galactose (34.4 %). The degree of polymerization of Astragali Radix oligosaccharides (APOS) was 2-16. APOS were identified as 1,4-glucooligosaccharides and 1,4-galactooligosaccharides. The findings of this study lay the foundation for further elucidation of structure-function relationships of APSs and provide guidance for the development of anti-inflammatory drugs.

Influence of the Original Concrete Strength and Initial Moisture Condition on the Properties Improvement of Recycled Coarse Aggregate via Accelerated Carbonation Reactions.

The physical and mechanical properties of recycled coarse aggregate (RCA) are worse than those of natural coarse aggregate (NCA), and the overall performance of recycled concrete prepared from RCA is worse than that of natural aggregate concrete. Treatment of RCA by CO2-accelerated carbonation effectively improves the macroscopic properties of RCA. The degree of influence of raw material factors, i.e., the original concrete strength (OCS) and initial moisture content (IMC) of RCA, on the carbonation of RCAs is very complex. Herein, an accelerated carbonation experiment for RCA with different material factors as variables was carried out to explore the influence of the abovementioned factors on the physical properties of carbonated recycled coarse aggregate (CRCA). By analyzing the microstructure of the RCA with the best modification effect before and after carbonation, the carbonation modification mechanism of the RCA was revealed. The physical performance indexes, including the apparent density, water absorption and carbonation rate, of the dried RCA with an OCS of C40 and C50 were significantly improved. The research results can provide basic data and theoretical support for promoting the popularization and application of RCA and recycled concrete in practical engineering.

In Situ Fabrication of SnO2 Nanowalls for Robust Acetylene Sensing at Low Temperature.

Acetylene (C2 H2 ) monitoring in real time and online is essential for erasing transformer risks and guaranteeing normal equipment operation and operator safety. This study examines the direct fabrication of ultrathin SnO2 nanowalls on Ag-Pd substrates using a simple solvothermal method that doesn't demand the use of any additional motivators or templates. The thickness and shape of the nanowalls can be controlled by varying the cetyl trimethyl ammonium bromide (CTAB) concentration in the solvent. As observed, the gas sensor (SnO2 -3) fabricated by 2.4 g CTAB exhibits superior gas-sensing features. This is primarily due to the hollow structure constructed by the arrangement of nanowalls, which delivers not only enough gas diffusion pathways but also enough reaction sites during the gas sensing processes. The findings suggest that low-cost SnO2 nanowalls created using a straightforward procedure could be taken into consideration as prospective candidates for use in industrial C2 H2 sensing applications.

Dual-Stimulus-Driven Dynamically Controllable [3]Rotaxane with Tunable Organic Room-Temperature Phosphorescence.

A dual-stimulus-driven stiff-stilbene-based dynamic [3]rotaxane has been facilely developed using the threading-stoppering strategy and exhibits reversible shuttling motions and bidirectional rotations upon encountering acid-base and distinct light stimulations, respectively. Herein, the two dibenzo-24-crown-8 macrocycles can undergo reversible switching motion between two different stations along the axle suffered from acid-base stimulation, and simultaneously, the two rotaxanes can also perform cis-trans rotations upon irradiation with distinct light. In other words, the constructed rotaxanes can conduct two modes of regular motions without interference. Interestingly, reciprocating switching motion of the rings along the axle enabled the rotaxanes to exhibit controllable and reversible photoisomerization speed, conversion yield, and quantum yield. Crucially, these rotaxanes also manifest adjustable solid-state organic room-temperature phosphorescence (RTP) and photoluminescence stimulated by dual factors (acid-base and diverse light), which are further applied in information encryption and anticounterfeiting. The presented study provides an instructive way for precisely boosting photoisomerization performances and the fabrication of dual-stimuli-induced molecular machines with functions of two-mode mechanical motions and controllable pure organic RTP switches.

Effects of different soil water holding capacities on vegetable residue return and its microbiological mechanism.

With the gradual expansion of the protected vegetable planting area, dense planting stubbles and increasing labor cost, the treatment of vegetable residues has become an urgent problem to be solved. Soil bacterial community structure plays an important role in vegetable residue return and is susceptible to environmental changes. Therefore, understanding the influences of different soil water holding capacities on plant residue decomposition and soil bacterial communities is important for biodegradation. During the whole incubation period, the weight loss ratio of plant residue with 100% water holding capacity was 69.60 to 75.27%, which was significantly higher than that with 60% water holding capacity in clay and sandy soil, indicating that high water holding capacity promoted the decomposition of plant residue. The degradation of lignin and cellulose was also promoted within 14 days. Furthermore, with the increase in soil water holding capacity, the contents of NH4+ increased to 5.36 and 4.54 times the initial value in the clay and sandy soil, respectively. The increase in napA and nrfA resulted in the conversion of NO3- into NH4+. The increase in water holding capacity made the bacterial network structure more compact and changed the keystone bacteria. The increase in water holding capacity also increased the relative abundance of Firmicutes at the phylum level and Symbiobacterium, Clostridium at the genus level, which are all involved in lignin and cellulose degradation and might promote their degradation. Overall, these findings provide new insight into the effects of different soil water holding capacities on the degradation of plant residues in situ and the corresponding bacterial mechanisms.

Photocontrolled Reversibly Chiral-Ordered Assembly Based on Cucurbituril.

Chirality transfer and regulation, accompanied by morphology transformation, arouse widespread interest for application in materials and biological science. Here, a photocontrolled supramolecular chiral switch is fabricated from chiral diphenylalanine (l-Phe-l-Phe, FF) modified with naphthalene (2), achiral dithienylethene (DTE) photoswitch (1), and cucurbit[8]uril (CB[8]). Chirality transfer from the chiral FF moiety of 2 to a charge-transfer (CT) heterodimer consisting of achiral guest 1 and achiral naphthalene (NP) in 2 has been unprecedented achieved via the encapsulation of CB[8]. On the contrary, chirality transfer from chiral FF to NP cannot be conducted in only guest 2. Crucially, induced circular dichroism of the heterodimer can be further modulated by distinct light, attributing to reversible photoisomerization of the DTE. Meanwhile, topological nanostructures are changed from one-dimensional (1D) nanofibers to two-dimensional (2D) nanosheets in the orderly assembling process of the heterodimer, which further achieved reversible interconversion between 2D nanosheets and 1D nanorods with tunable-induced chirality stimulated by diverse light.

Risk of Fracture and Osteoporosis in Patients With COPD and Inhaled Corticosteroids Treatment.

BACKGROUND: There are disputes whether inhaled corticosteroids (ICS) increase the incidence of fracture or osteoporosis among patients with COPD. The aim of this meta-analysis was to assess the effect of ICS treatment on the risk of fracture and osteoporosis in subjects with COPD. METHODS: This study included parallel-group randomized controlled trials (RCTs) comparing ICS and control (non-ICS) therapy for subjects with COPD that reported adverse events including fractures or osteoporosis. Studies were found using MEDLINE/PubMed, Embase, and Cochrane Library databases between 1998-September 2022. Pooled risk ratios (RRs) and 95% CIs were calculated for primary outcomes. RESULTS: A total of 61,380 participants from 26 RCTs were included in the meta-analysis. Exposure to ICS did not increase the risk of fracture (RR 1.10 [95% CI 0.98-1.23], P = .10) or osteoporosis risk (RR 0.93 [95% CI 0.49-1.79], P = .84) in subjects with COPD. CONCLUSIONS: ICS use did not increase the incidence of fracture or osteoporosis in subjects with COPD.

Post-myocardial infarction fibrosis: Pathophysiology, examination, and intervention.

Cardiac fibrosis plays an indispensable role in cardiac tissue homeostasis and repair after myocardial infarction (MI). The cardiac fibroblast-to-myofibroblast differentiation and extracellular matrix collagen deposition are the hallmarks of cardiac fibrosis, which are modulated by multiple signaling pathways and various types of cells in time-dependent manners. Our understanding of the development of cardiac fibrosis after MI has evolved in basic and clinical researches, and the regulation of fibrotic remodeling may facilitate novel diagnostic and therapeutic strategies, and finally improve outcomes. Here, we aim to elaborate pathophysiology, examination and intervention of cardiac fibrosis after MI.

Template Based Synthesis of Porous Graphdiyne Nanosheet for Reversible and Fast NO2 Detection by UV Irradiation.

Two-dimensional graphdiyne (GDY) formed by sp and sp2 hybridized carbon has been found to be an efficient toxic gas sensing material by density functional theory (DFT). However, little experimental research concerning its gas sensing capability has been reported owing to the complex preparation process and harsh experimental conditions. Herein, porous GDY nanosheets are successfully synthesized through a facile solvothermal synthesis technique by using CuO microspheres (MSs) as both template and source of catalyst. The porous GDY nanosheets exhibit a broadband optical absorption, rendering it suitable for the light-driven optoelectronic gas sensing applications. The GDY-based gas sensor was demonstrated to have excellent reversible to NO2 behaviors at 25 °C for the first time. More importantly, higher response value and faster response-recovery time once exposed to NO2 gas molecules are achieved by the illumination of UV light. In this way, our work paves the way for the exploration of GDY-based gas detection experimentally.

A Comprehensive Investigation into the Crystallology, Molecule, and Quantum Chemistry Properties of Two New Hydrous Long-Chain Dibasic Ammonium Salts CnH2n+8N2O6 (n = 35 and 37).

Through the salification reaction of carboxylation, successful attachment of the long-chain alkanoic acid to the two ends of 1,3-propanediamine was realized, which enabled the doubling of the long-chain alkanoic acid carbon chain. Hydrous 1,3-propanediamine dihexadecanoate (abbreviated as 3C16) and 1,3-propanediamine diheptadecanoate (abbreviated as 3C17) were synthesized afterward, and their crystal structures were characterized by the X-ray single crystal diffraction technique. By analyzing their molecular and crystal structure, their composition, spatial structure, and coordination mode were determined. Two water molecules played important roles in stabilizing the framework of both compounds. Hirshfeld surface analysis revealed the intermolecular interactions between the two molecules. The 3D energy framework map presented the intermolecular interactions more intuitively and digitally, in which dispersion energy plays a dominant role. DFT calculations were performed to analyze the frontier molecular orbitals (HOMO-LUMO). The energy difference between the HOMO-LUMO is 0.2858 eV and 0.2855 eV for 3C16 and 3C17, respectively. DOS diagrams further confirmed the distribution of the frontier molecular orbitals of 3C16 and 3C17. The charge distributions in the compounds were visualized using a molecular electrostatic potential (ESP) surface. ESP maps indicated that the electrophilic sites are localized around the oxygen atom. The crystallographic data and parameters of quantum chemical calculation in this paper will provide data and theoretical support for the development and application of such materials.

SUPER Score Contributes to Warning and Management in Early-Stage COVID-19.

Background: Some COVID-19 patients deteriorate to severe cases with relatively higher case-fatality rates, which increases the medical burden. This necessitates identification of patients at risk of severe disease. Early assessment plays a crucial role in identifying patients at risk of severe disease. This study is to assess the effectiveness of SUPER score as a predictor of severe COVID-19 cases. Methods: We consecutively enrolled COVID-19 patients admitted to a comprehensive medical center in Wuhan, China, and recorded clinical characteristics and laboratory indexes. The SUPER score was calculated using parameters including oxygen saturation, urine volume, pulse, emotional state, and respiratory rate. In addition, the area under the receiver operating characteristic curve (AUC), specificity, and sensitivity of the SUPER score for the diagnosis of severe COVID-19 were calculated and compared with the National Early Warning Score 2 (NEWS2). Results: The SUPER score at admission, with a threshold of 4, exhibited good predictive performance for early identification of severe COVID-19 cases, yielding an AUC of 0.985 (95% confidence interval [CI] 0.897-1.000), sensitivity of 1.00 (95% CI 0.715-1.000), and specificity of 0.92 (95% CI 0.775-0.982), similar to NEWS2 (AUC 0.984; 95% CI 0.895-1.000, sensitivity 0.91; 95% CI 0.587-0.998, specificity 0.97; 95% CI 0.858-0.999). Compared with patients with a SUPER score<4, patients in the high-risk group exhibited lower lymphocyte counts, interleukin-2, interleukin-4 and higher fibrinogen, C-reactive protein, aspartate aminotransferase, and lactate dehydrogenase levels. Conclusions: In conclusion, the SUPER score demonstrated equivalent accuracy to the NEWS2 score in predicting severe COVID-19. Its application in prognostic assessment therefore offers an effective early warning system for critical management and facilitating efficient allocation of health resources.

A ROCK1 Inhibitior Fasudil Alleviates Cardiomyocyte Apoptosis in Diabetic Cardiomyopathy by Inhibiting Mitochondrial Fission in a Type 2 Diabetes Mouse Model.

Diabetes mellitus (DM) often involves cardiovascular complications; however, treatment regimens are limited. ROCK1 (rho-associated coiled-coil containing protein kinase 1) serves as a pathological factor in several diabetic complications. Herein, we aimed to explore the effect of Fasudil (a ROCK1 inhibitor) on the progress of cardiac dysfunction in type 2 DM (T2DM), and to explore the possible mechanisms. Type II diabetic mice models were established by inducing insulin resistance through a high-fat diet combined with low-dose streptozotocin (STZ) injection. NMCMs (neonatal mouse ventricular cardiac myocytes) in the control group were treated with 5.5 mM glucose, while those in the High Glucose (HG) group were treated with 33 mM glucose and 10 nmol/L insulin. In vivo, we found that type 2 diabetes enhanced the expression and activation of ROCK1 (p < 0.05). The ROCK1 inhibitor, Fasudil, prevented cardiac dysfunction, fibrosis, oxidative stress and myocardial ultrastructural disorders (p < 0.05) in the diabetic mice. In vitro, ROCK1 was upregulated in HG-induced cardiomyocytes, and ROCK1 inhibition using Fasudil reversed the increased apoptosis, consistent with in vivo results. Mechanistically, ROCK1 inhibition abrogated apoptosis, relieved mitochondrial fission, and efficiently attenuated the escalated production of reactive oxygen species in vitro and in vivo. The content of Ser616-phosphorylated dynamin-related protein 1 (Drp1) increased while ROCK1 led to apoptosis in HG-treated cardiomyocytes, which could be partly neutralized by ROCK1 inhibition with Fasudil, consistent with the in vivo results. Fasudil attenuated the cardiac dysfunction in diabetes by decreasing excessive mitochondrial fission via inhibiting Drp1 phosphorylation at serine 616.

Hydrogen therapy after resuscitation improves myocardial injury involving inhibition of autophagy in an asphyxial rat model of cardiac arrest.

Hydrogen (H2) therapy is a therapeutic strategy using molecular H2. Due to its ability to regulate cell homeostasis, H2 therapy has exhibited marked therapeutic effects on a number of oxidative stress-associated diseases. The present study investigated the effectiveness of H2 therapy in protecting against myocardial injury in a rat model of asphyxial cardiac arrest and cardiopulmonary resuscitation. Rats underwent 10-min asphyxia-induced cardiac arrest (CA) and cardiopulmonary resuscitation (CPR), and were randomly divided into control and H2 therapy groups. After resuscitation, the H2 therapy group was administered room air mixed with 2% H2 gas for respiration. During CA/CPR, the arterial pressure and heart rate were measured every minute. Survival rate, cardiac function, myocardial injury biomarkers creatine kinase-MB and cardiac troponin-T, and histopathological changes were evaluated to determine the protective effects of H2 therapy in CA/CPR. Immunohistochemistry and western blot analysis were used to determine the expression levels of autophagy-associated proteins. In vitro, H9C2 cells were subjected to hypoxia/reoxygenation and H2-rich medium was used in H2 treatment groups. Western blotting and immunofluorescence were used to observe the expression levels of autophagy-associated proteins. Moreover, an adenovirus-monomeric red fluorescent protein-green fluorescent protein-LC3 construct was used to explore the dynamics of autophagy in the H9C2 cells. The results showed that H2 therapy significantly improved post-resuscitation survival and cardiac function. H2 therapy also improved mitochondrial mass and decreased autophagosome numbers in cardiomyocytes after resuscitation. The treatment inhibited autophagy activation, with lower expression levels of autophagy-associated proteins and decreased autophagosome formation in vivo and vitro. In conclusion, H2 gas inhalation after return of spontaneous circulation improved cardiac function via the inhibition of autophagy.

Relationship Between the Structure and Immune Activity of Components From the Active Polysaccharides APS-II of Astragali Radix by Enzymolysis of Endo α-1,4-Glucanase.

Astragali Radix polysaccharides (APSs) have a wide range of biological activities. Our preliminary experiment showed that APS-Ⅱ (10 kDa) was the main immunologically active component of APSs. However, the characteristic structure related to activity of APS-Ⅱ needs further verification and clarification. In this study, APS-II was degraded by endo α-1,4-glucosidase. The degraded products with different degrees of polymerization [1-3 (P1), 3-6 (P2), 7-14 (P3), and 10-18 (P4)] were obtained using a polyacrylamide gel chromatography column. The structural features of the different products were characterized by HPGPC, monosaccharide composition, Fourier transform infrared spectrum, GC-MS, nuclear magnetic resonance, and UPLC-ESI-QTOF-MS analysis. Specific immune and non-specific immune cell tests were used to identify the most immunogenic fractions of the products. The backbone of P4 was speculated to be α-D-1,4-linked glucans and rich in C2 (25.34%) and C6 (34.54%) branches. Immune screening experiments indicated that the activity of P4 was better than that of APS-II and the other three components. In this research, the relationship between the structure of APS-Ⅱ and the immune activity from the degradation level of polysaccharides was studied, laying a foundation for the quality control and product development of APSs.

A sensitive electrochemiluminescence biosensor for assay of cancer biomarker (MMP-2) based on NGQDs-Ru@SiO2 luminophore.

A sensitive biosensor that can be used for the determination of matrix metalloproteinase 2 (MMP-2) was proposed. The biosensor was developed by using an excellent self-enhanced nanocomposites as an illuminant and a peptide as a recognition element. For the electrostatic attraction between Ru(bpy)32+ and nitrogen-doped graphene quantum dots (NGQDs), the self-enhanced electrochemiluminescence (ECL) nanocomposites of NGQDs-Ru(bpy)32+-doped silica nanoparticles (NGQDs-Ru@SiO2) were synthesized through a simple sol-gel process. Then, a specific peptide (labeled sulfhydryl) was combined with the self-enhanced ECL nanocomposites (carboxyl in NGQDs) via acylation reaction to obtain the peptide-NGQDs-Ru@SiO2 nanoprobe, which was fabricated onto the gold electrode surface via Au-S bond. The peptide of the ECL nanoprobe was exposed to cleavage in the presence of MMP-2, which caused the signal substance to move farther away from the electrode, leading to a decrease of the ECL signal. The proposed NGQDs-Ru@SiO2-labeled peptide ECL biosensor displayed a lower detection limit of 6.5 pg mL-1 than those of reported ECL methods. The proposed biosensor provided an outlook for future applications in other disease-associated biomarkers.

Prostaglandin E1 attenuates post­cardiac arrest myocardial dysfunction through inhibition of mitochondria­mediated cardiomyocyte apoptosis.

Post­cardiac arrest myocardial dysfunction (PAMD) is a leading cause of death in patients undergoing resuscitation patients following cardiac arrest (CA). Although prostaglandin E1 (PGE1) is a clinical drug used to mitigate ischemia injury, its effect on PAMD remains unknown. In the present study, the protective effects of PGE1 on PAMD were evaluated in a rat model of CA and in a hypoxia­reoxygenation (H/R) in vitro model. Rats were randomly assigned to CA, CA+PGE1 or sham groups. Asphyxia for 8 min followed by cardiopulmonary resuscitation were performed in the CA and CA+PGE1 groups. PGE1 was intravenously administered at the onset of return of spontaneous circulation (ROSC). PGE1 treatment significantly increased the ejection fraction and cardiac output within 4 h following ROSC and improved the survival rate, compared with the CA group. Moreover, PGE1 inactivated GSK3ß, prevented mitochondrial permeability transition pore (mPTP) opening, while reducing cytochrome c and cleaved caspase­3 expression, as well as cardiomyocyte apoptosis in the rat model. To examine the underlying mechanism, H/R H9c2 cells were treated with PGE1 at the start of reoxygenation. The changes in GSK3ß activity, mPTP opening, cytochrome c and cleaved caspase­3 expression, and apoptosis of H9c2 cells were consistent with those noted in vivo. The results indicated that PGE1 attenuated PAMD by inhibiting mitochondria­mediated cardiomyocyte apoptosis.

Aldehyde dehydrogenase 2 preserves mitochondrial morphology and attenuates hypoxia/reoxygenation-induced cardiomyocyte injury.

BACKGROUND: Disturbance of mitochondrial fission and fusion (termed mitochondrial dynamics) is one of the leading causes of ischemia/reperfusion (I/R)-induced myocardial injury. Previous studies showed that mitochondrial aldehyde dehydrogenase 2 (ALDH2) conferred cardioprotective effect against myocardial I/R injury and suppressed I/R-induced excessive mitophagy in cardiomyocytes. However, whether ALDH2 participates in the regulation of mitochondrial dynamics during myocardial I/R injury remains unknown. METHODS: In the present study, we investigated the effect of ALDH2 on mitochondrial dynamics and the underlying mechanisms using the H9c2 cells exposed to hypoxia/reoxygenation (H/R) as an in vitro model of myocardial I/R injury. RESULTS: Cardiomyocyte apoptosis was significantly increased after oxygen-glucose deprivation and reoxygenation (OGD/R), and ALDH2 activation largely decreased the cardiomyocyte apoptosis. Additionally, we found that both ALDH2 activation and overexpression significantly inhibited the increased mitochondrial fission after OGD/R. Furthermore, we found that ALDH2 dominantly suppressed dynamin-related protein 1 (Drp1) phosphorylation (Ser616) and adenosine monophosphate-activated protein kinase (AMPK) phosphorylation (Thr172) but not interfered with the expression levels of mitochondrial shaping proteins. CONCLUSIONS: We demonstrate the protective effect of ALDH2 against cardiomyocyte H/R injury with a novel mechanism on mitochondrial fission/fusion.

Differentially expressed lncRNAs, miRNAs and mRNAs with associated ceRNA networks in a mouse model of myocardial ischemia/reperfusion injury.

Non­coding RNAs, including long non­coding RNAs (lncRNAs) and microRNAs (miRNAs/miRs), have significant regulatory effects on a number of biological processes in myocardial ischemia/reperfusion (I/R) injury, including cell differentiation, proliferation and apoptosis. In the present study, the expression levels of lncRNAs, miRNAs and mRNAs were evaluated in a mouse model of myocardial I/R injury. The potential functions of these differentially expressed genes were then analyzed via Gene Ontology and pathway analyses. Additionally, the interactions between lncRNA­miRNA­mRNA were predicted by constructing a competing endogenous RNA regulatory network. It was found that 14,366 lncRNAs, 151 miRNAs and 9,377 mRNAs were differentially expressed in mice hearts after I/R compared with the Sham group (fold change >2; P<0.05). The results indicated that these differentially expressed genes were involved in multiple molecular functions, including 'guanosine diphosphate binding', 'RNA polymerase II carboxy­terminal domain kinase activity', 'TATA­binding protein­class protein binding', 'nicotinamide adenine dinucleotide binding' and 'protein phosphatase type 2A regulator activity'. The interactions between lncRNA­miRNA­mRNA, including five lncRNAs, 38 miRNAs and 196 mRNAs, were predicted, specifically Gm12040­mmu­miR­125a­5p­decapping mRNA 1B, Rpl7l1­ps1­mmu­miR­124­3p­G protein­coupled receptor 146, Gm11407­mmu­miR­190a­5p­homeobox and leucine zipper encoding (HOMEZ), 1600029O15Rik­mmu­miR­132­3p­HOMEZ and AK155692­mmu­miR­1224­3p­activating transcription factor 6ß. Collectively, these findings provided novel insights for future research on lncRNAs, miRNAs and mRNAs in myocardial I/R injury.

Aldehyde Dehydrogenase 2 Protects Against Post-Cardiac Arrest Myocardial Dysfunction Through a Novel Mechanism of Suppressing Mitochondrial Reactive Oxygen Species Production.

Post-cardiac arrest myocardial dysfunction significantly contributes to early mortality after the return of spontaneous circulation. However, no effective therapy is available now. Aldehyde dehydrogenase 2 (ALDH2) enzyme has been shown to protect the heart from aldehyde toxicity such as 4-hydroxy-2-nonenal (4-HNE) and oxidative stress. In this study, we evaluated the effect of enhanced activity or expression of ALDH2 on post-cardiac arrest myocardial dysfunction and survival in a rat cardiac arrest model. Furthermore, we elucidated the underlying mechanisms with a focus on mitochondrial reactive oxygen species (ROS) production in a cell hypoxia/reoxygenation model. A total of 126 rats were used for the ALDH2 activation or cardiac overexpression of ALDH2 studies. Randomization was done 10 min before the respective agonist injection or in vivo gene delivery. We showed that enhanced activity or expression of ALDH2 significantly improved contractile function of the left ventricle and survival rate in rats subjected to cardiac arrest-cardiopulmonary resuscitation procedure. Moreover, ALDH2 prevented cardiac arrest-induced cardiomyocyte death from apoptosis and mitochondrial damage. Mechanistically, 4-HNE, a representative substrate of ALDH2, was dominantly increased in the hypoxia/reoxygenation-exposed cardiomyocytes. Direct addition of 4-HNE led to significantly augmented succinate accumulation and mitochondrial ROS production. Through metabolizing 4-HNE, ALDH2 significantly inhibited mitochondrial ROS production. Our findings provide compelling evidence of the cardioprotective effects of ALDH2 and therapeutic targeting this enzyme would provide an important approach for treating post-cardiac arrest myocardial dysfunction.