Schottky Junctions with Bi@Bi2MoO6 Core-Shell Photocatalysts toward High-Efficiency Solar N2-to-Ammonnia Conversion in Aqueous Phase.

The photocatalytic nitrogen reduction reaction (NRR) in aqueous solution is a green and sustainable strategy for ammonia production. Nonetheless, the efficiency of the process still has a wide gap compared to that of the Haber-Bosch one due to the difficulty of N2 activation and the quick recombination of photo-generated carriers. Herein, a core-shell Bi@Bi2MoO6 microsphere through constructing Schottky junctions has been explored as a robust photocatalyst toward N2 reduction to NH3. Metal Bi self-reduced onto Bi2MoO6 not only spurs the photo-generated electron and hole separation owing to the Schottky junction at the interface of Bi and Bi2MoO6 but also promotes N2 adsorption and activation at Bi active sites synchronously. As a result, the yield of the photocatalytic N2-to-ammonia conversion reaches up to 173.40 µmol g-1 on core-shell Bi@Bi2MoO6 photocatalysts, as much as two times of that of bare Bi2MoO6. This work provides a new design for the decarbonization of the nitrogen reduction reaction by the utilization of renewable energy sources.

Photothermal Synergistic Catalysis over Defective Zn3In2S6 for CO2 Fixation.

Carbon dioxide (CO2) cycloaddition not only produces highly valued cyclic carbonate but also utilizes CO2 as C1 resources with 100% atomic efficiency. However, traditional catalytic routes still suffer from inferior catalytic efficiency and harsh reaction conditions. Developing multienergy-field catalytic technology with expected efficiency offers great opportunity for satisfied yield under mild conditions. Herein, Zn3In2S6 with sulfur vacancies (Sv) was fabricated with the assistance of cetyltrimethylammonium bromide (CTAB), which is further employed for photothermally driven CO2 cycloaddition first. Photoluminescence spectroscopy and photoelectrochemical characterization demonstrated its superior separation kinetics of photoinduced carriers induced by defect engineering. The temperature-programmed desorption (TPD) technique indicated its excellent Lewis acidity-basicity characters. Due to the combination of above merits from photocatalysis and thermal catalysis, defective Zn3In2S6-Sv achieved a yield as high as 73.2% for cyclic carbonate at 80 °C under blue LED illumination within 2 h (apparent quantum yield of 0.468% under illumination of 380 nm monochromatic light at 36 mW·cm-2), which is 2.9, 2.0, and 6.9 times higher than that in dark conditions and those of pristine Zn3In2S6 and industrial representative tetrabutylammonium bromide (TBAB) thermal-catalysis process under the same conditions, respectively. The synergistic reaction path of photocatalysis and thermal catalysis was discriminated by theoretical calculation. This work provides new insights into the photothermal synergistic catalysis CO2 cycloaddition with defective ternary metal sulfides.

Mineralization versus polymerization pathways in heterogeneous Fenton-like reactions.

Fenton reaction has been widespread application in water purification due to the excellent oxidation performances. However, the poor cycle efficiency of Fe(III)/Fe(II) is one of the biggest bottlenecks. In this study, graphite (GP) was used as a green carbon catalyst to accelerate Fenton-like (H2O2/Fe3+ and persulfate/Fe3+) reactions by promoting ferric ion reduction and intensifying diverse peroxide activation pathways. Significantly, the carboxyl group on GP anchors iron ions to form GP-COOFe(III) which promote persulfate adsorption to form surface complexes and induce an electron transfer pathway (ETP). While the electron-rich hydroxyl and carbonyl groups will combine to from GP-COFe(II), a reductive intermediate to activate peroxide to generate free radicals (from H2O2 and PDS) or high-value iron [Fe(IV)] (from PMS). Consequently, different pathways lead to distinct degree of oxidation: i) radicals in H2O2/Fe3+/GP prefer to mineralize bisphenol A (BPA) with no selectivity; ii) Fe(IV) in PMS/Fe3+/GP partially oxidizes BPA but cannot open the aromatic ring; iii) ETP in PMS/ or PDS/Fe3+/GP drives coupling reactions to form polymeric products covered on catalyst surface. Thus, rational engineering surface functionality of graphite and selecting proper peroxides can realize on-demand selectivity and oxidation capacity in Fenton-like systems.

The Effects of Different Puncture Points on Labor Analgesia Onset: Study Protocol for a Randomized Controlled Trial.

Purpose: Parturients suffer severe pain during the stages of labor, especially the first and second. Epidural anesthesia is an effective method to alleviate labor pain. L2-3, L3-4 and L4-5 spaces have been reported to be the recommendable puncture points owing to the adequate analgesia effect and high safety. However, the speed of pain alleviation via the three points has hardly been determined, which is of great importance to parturients. Thus, the aim of this study is to compare the onset time of parturients' painless uterine contraction after epidural labor analgesia through different puncture points. Study Design and Methods: It is a prospective, randomized, controlled, and subject- and assessor-blinded study. Totally, 150 subjects scheduled for vaginal delivery are going to be randomly assigned into the L2-3 and L3-4 group. Puncture point in L2-3 group is lumbar 2-3 space, while in L3-4 group it is lumbar 3-4 space. Analgesia initiation and maintenance are the same between the two groups. Primary outcome will be percentage of painless uterine contraction 15 min after epidural labor analgesia initiation. Secondary outcomes will be the sensory blocking level, motor blocking score, adverse effects of parturients, drug liquid consumption in unit interval, apgar score and degree of satisfaction of the parturients. Discussion: This study estimates the onset time of parturients' painless uterine contraction after epidural labor analgesia through L2-3 or L3-4 space. The results may provide a better choice to relieve labor pain as soon as possible.

Thermodynamic and Kinetic Behaviors of Persulfate-Based Electron-Transfer Regime in Carbocatalysis.

A carbon-based advanced oxidation process is featured for the nonradical electron-transfer pathway (ETP) from electron-donating organic compounds to activated persulfate complexes, enabling it as a green technology for the selective oxidation of organic pollutants in complex water environments. However, the thermodynamic and kinetic behaviors of the nonradical electron-transfer regime had been ambiguous due to a neglect of the influence of pH on the mechanisms. In this study, three kinds of organic pollutants were divided in the carbon-based ETP regime: (i) physio-adsorption, (ii) adsorption-dominated ETP (oxidation rate slightly surpasses adsorption rate), and (iii) oxidation-dominated ETP (oxidation rate outpaces the adsorption rate). The differential kinetic behaviors were attributed to the physicochemical properties of the organic pollutants. For example, the hydrophobicity, molecular radius, and positive electrostatic potential controlled the mass-transfer process of the adsorption stage of the reactants (peroxydisulfate (PDS) and organics). Meanwhile, other descriptors, including the Fukui index, oxidation potential, and electron cloud density regulated the electron-transfer processes and thus the kinetics of oxidation. Most importantly, the oxidation pathways of these organic pollutants could be altered by adjusting the water chemistry. This study reveals the principles for developing efficient nonradical systems to selectively remove and recycle organic pollutants in wastewater.

BiOI/Bi2MoO6 p-n Junction to Enhance Visible Light Photocatalytic Activity toward Environmental Remediation.

Photocatalytic degradation of organic pollutants via semiconductors with high visible light response and effective carrier separation is an economical and green route to greatly achieve environmental remediation. Herein, an efficient BiOI/Bi2MoO6 p-n heterojunction was in situ fabricated through hydrothermal method by substituting Mo7O246- species for I ions. The characteristic p-n heterojunction exhibited a strongly enhanced visible light responsive absorption from 500 to 700 nm owing to the narrow band gap of BiOI and a greatly effective separation of photoexcited carriers because of the built-in electric field on the interface between BiOI and Bi2MoO6. Moreover, the flower-like microstructure also promoted the adsorption of organic pollutants owing to the large surface area (about 10.36 m2/g), good for further photocatalytic degradation. As a result, BiOI/Bi2MoO6 p-n heterojunction showed an excellent photocatalytic activity of RhB of almost 95% in a short time of 90 min under wavelength longer than 420 nm, 2.3 and 2.7 times higher compared with single BiOI and Bi2MoO6, respectively. This work offers a promising approach to purify the environment through the utilization of solar energy by constructing efficient p-n junction photocatalysts.

Nanostructured conversion-type anode materials of metal-organic framework-derived spinel XMn2O4 (X = Zn, Co, Cu, Ni) to boost lithium storage.

Bimetallic spinel transition metal oxides play a major part in actualizing eco-friendly electrochemical energy storage systems (ESSs). However, structural precariousness and low electrochemical capacitance restrict their actual implementation in lithium-ion batteries (LIBs). To address these demerits, the sacrificial template approach has been considered as a prospective way to strengthen electrochemical stability and rate performance. Herein, metal-organic frameworks (MOFs) derived XMn2O4-BDC (H2BDC = 1,4-dicarboxybenzene, X = Zn, Co, Cu, Ni) are prepared by a hydrothermal approach in order to discover the effects of various metal cations on the electrochemical performance. Among them, ZnMn2O4-BDC displays best electrochemical properties (1321.5 mAh g-1 at the current density of 0.1 A g-1 after 300 cycles) and high efficiency with accelerated Li+ diffusivity. Density functional theory (DFT) calculations confirm the ZnMn2O4 possesses the weakest adsorption energy on Li+ with a minimized value of -0.92 eV. In comparison with other XMn2O4 through traditional fabrication method, MOF-derived XMn2O4-BDC possesses a higher number of Li+ transport channels and better electric conductivity. This tactic provides a feasible and effective method for preparing bimetallic transition metal oxides and enhances energy storage applications.

Mu-opioid receptor alleviated ferroptosis in hepatic ischemia-reperfusion injury via the HIF-1α/KCNQ1OT1 axis.

Ferroptosis is the ideal therapeutic target for hepatic ischemia and reperfusion injury (HIRI). The µ opioid receptor (MOR) is associated with ferroptosis in HIRI. We aimed to determine the ferroptosis-related therapeutic mechanism of MOR in HIRI. A model of HIRI was established in BALB/c mice. Primary hepatocytes isolated from mice were stimulated by hypoxia/reoxygenation (H/R). Changes in histopathology were determined by H&E staining. Alterations in ferroptosis were evaluated by malondialdehyde (MDA), iron, glutathione (GSH), ACSL4, GPX4, and mitochondrial morphology. ALT and AST were used to determine hepatic function. First, we found that hepatic ischemia/reperfusion (I/R) induced the destruction of hepatic tissue structure and dead hepatocytes and determined that ferroptosis occurred in vivo and in vitro. During HIRI, the expression levels of HIF-1α and KCNQ1OT1 were significantly upregulated. We demonstrated that sufentanil improved the damage in the liver and hepatocytes undergoing I/R. Importantly, sufentanil inhibited ferroptosis in HIRI. In addition, sufentanil downregulated the expression levels of HIF-1α and KCNQ1OT1 in HIRI. Increases in HIF-1α and KCNQ1OT1 reversed the role of sufentanil in ferroptosis and HIRI. Subsequently, we determined that HIF-1α could activate the transcription of KCNQ1OT1 by binding to its promoter. In addition, KCNQ1OT1 was demonstrated to enhance ACSL4 stability by interacting with SRSF1. Finally, we observed that KCNQ1OT1 downregulation protected hepatocytes from hepatic I/R and inhibited ferroptosis. KCNQ1OT1 upregulation aggravated ferroptosis and hepatic injury during I/R. However, decreases in ACSL4 and SRSF1 reversed the harmful role of KCNQ1OT1 upregulation in HIRI. MOR alleviated ferroptosis in HIRI via the HIF-1α/KCNQ1OT1 axis.

Silencing lncRNA KCNQ1OT1 reduced hepatic ischemia reperfusion injury-induced pyroptosis by regulating miR-142a-3p/HMGB1 axis.

BACKGROUND: Based on pre-existing evidence, KCNQ1OT1 has been pointed out to be closely related to myocardial and cerebral ischemia reperfusion injury diseases. Herein, the objective of our study is to probe into the potential function as well as the underlying mechanism of KCNQ1OT1 on hepatic ischemia reperfusion injury (HIRI). METHODS: Using C57BL/6 J mice and primary mouse hepatocytes were conducted to establish HIRI model in vivo and in vitro. Cell viability was examined using CCK-8 assay and EdU assay. Flow cytometric analysis was performed to evaluate the pyroptosis. Dual-luciferase reporter assay was employed to verify the interaction relationships. qRT-PCR and Western blot were adopted to analyze the mRNA and protein level. Histopathological alteration of liver tissue was evaluated by HE staining. Immunohistochemistry (IHC) was performed to measure NLRP3 and caspase 1. RESULTS: Our data revealed that KCNQ1OT1 expression was ascending in hepatic tissue of HIRI mouse. Moreover, deprivation of KCNQ1OT1 mitigated I/R-induced hepatic injury and pyroptosis in vivo. Further experiments demonstrated that silencing KCNQ1OT1 promoted proliferation and inhibited pyroptosis in hypoxia/reoxygenation (H/R)-induced primary mouse hepatocytes. Mechanistically, KCNQ1OT1 functioned as a competing endogenous RNA which sponged miR-142a-3p, therefore promoted HMGB1 expression to activate TLR4/NF-κB signaling pathway in HIRI. CONCLUSION: LncRNA KCNQ1OT1 elevated HMGB1 expression through binding to miR-142a-3p, thereby promoting pyroptosis in HIRI.

Electron-transfer-based peroxymonosulfate activation on defect-rich carbon nanotubes: Understanding the substituent effect on the selective oxidation of phenols.

Nanocarbon-based persulfate oxidation technologies are promising for green elimination of phenolic pollutants. Previous studies revealed the electron transfer via defective carbon nanotube (CNTs) for selective oxidation of various phenols. However, an underlying relationship between the molecular structure of phenols and the selectivity of electron transfer-induced oxidation has not been well understood. Herein, we report that defect-rich CNTs could initiate electron-transfer regime from phenols to peroxymonosulfate (PMS), resulting in the efficient degradation of phenols. Further studies uncover a distinctive substituent group-dependent selective oxidation of phenols via the CNT-mediated electron transfer process. Specifically, the degradation rate of para-substituted phenols with electron-donating groups (e.g., -NH2 and -OCH3) is faster than those with electron-withdrawing groups (e.g., -NO2 and -COOH). For a kind of substituted phenols, the substituent position has a great influence on the phenols degradation and their degradation rates follow this sequence: para > ortho > meta -position. Besides, increasing the number of the substituent group can accelerate the degradation of substituted phenols. This study elucidates the substituent effect on the electron transfer-dominated selective oxidation of phenols for the first time, which guides the application of carbon/persulfate system for the targeted remediation of phenols-polluted wastewater.

Preparation, Characterization and Application of Epitaxial Grown BiOBr (110) Film on ZnFe2O4 Surface with Enhanced Photocatalytic Fenton Oxidation Properties.

A novel BiOBr photocatalyst was epitaxially grown in situ onto the surface of ZnFe2O4, a ferroelectric material with a strong polarization effect. The formatted BiOBr/ZnFe2O4 composite (BOB/ZFO) showed excellent photocatalytic degradation performance of tetracycline antibiotics (TCs). One of the composites with ZnFe2O4 content of 10% (BOB/ZFO-10) showed the best properties; the degradation efficiency of TCs upon visible light irradiation for 180 min was 99.2%, which was 3.58 times higher than that of pure phase BiOBr. The functions of ZnFe2O4 are assumed to be such that the addition of this ferroeletric material not only regulated the spontaneous polarization of BiOBr in the process of synthesis, but also resulted in the construction of Z-scheme heterostructures due to the appropriate staggered band structure of BiOBr and ZnFe2O4. In the presence of ferroelectric material ZnFe2O4, the local structure of BiOBr may be distorted accordingly, resulting in preferential growth of a (110) crystal facet of BiOBr and enhancement of spontaneous polarization, which promotes the efficient separation of photogenerated electron-hole pairs of ZnFe2O4 and BiOBr, and therefore enhances the redox capacity of the photocatalytic degradation of organic pollutants.

Octreotide ameliorates hepatic ischemia-reperfusion injury through SNHG12/TAF15-mediated Sirt1 stabilization and YAP1 transcription.

BACKGROUND: Hepatic ischemia-reperfusion (HIR) injury is a pathological condition initiated by interrupted hepatic blood supply and exaggerated after reperfusion, which is one of the most lethal risks in liver transplantation and other liver surgeries. We aimed to investigate the protective mechanism of octreotide (Oct) against HIR injury. METHODS: The function of Oct was evaluated in the in vivo mouse model of HIR injury. Histological examinations were performed to assess the pathological changes. Serum parameters including ALT and AST were measured to evaluate the liver damage. qRT-PCR and western blot analysis were employed to determine the levels of long non-coding RNA SNHG12 (SNHG12) and autophagy or apoptosis-related proteins. RNA pull-down and RIP assays were used to verify the interaction between SNHG12 and TAF15. The transcriptional regulation of TAF15 in YAP1 was validated by ChIP and luciferase reporter assays. RESULTS: In the in vivo HIR injury model, Oct efficiently alleviated HIR-caused hepatic damage by suppressing apoptosis and activating autophagy. However, silencing of SNHG12 abrogated the protective effects of Oct via inactivating autophagy. Further mechanism investigation revealed that SNHG12 promoted the stabilization of Sirt1 and increased YAP1 transcriptional activity via interacting with TAF15. Up-regulation of Sirt1 and YAP1 was essential for maintaining the protective effect of Oct against HIR injury through increasing autophagic flux and suppressing apoptosis. CONCLUSIONS: Oct-induced up-regulation of SNHG12 attenuated HIR injury via promoting Sirt1 stabilization and YAP1 transcription to activate autophagy and repress apoptosis.

Enhanced Photo-Assisted Fenton Degradation of Antibiotics over Iron-Doped Bi-Rich Bismuth Oxybromide Photocatalyst.

Herein, combining photocatalysis and Fenton oxidation, a photo-assisted Fenton system was conducted using Fe-doped Bi4O5Br2 as a highly efficient photocatalyst to realize the complete degradation of Tetracycline antibiotics under visible light. It has been observed that the optimized photocatalyst 5%Fe-doped Bi4O5Br2 exhibits a degradation efficiency of 100% for Tetracycline with H2O2 after 3 h visible-light irradiation, while a degradation percentage of 59.8% over the same photocatalyst and 46.6% over pure Bi4O5Br2 were obtained without the addition of H2O2 (non-Fenton process). It is unambiguous that a boost photo-assisted Fenton system for the degradation of Tetracycline has been established. Based on structural analysis, it demonstrated that the Fe atoms in place of the Bi sites may result in the distortion of the local structure, which induced the occurrence of the spontaneous polarization and thus enhanced the built-in electric field. The charge separation efficiency is enhanced, and the recombination of electrons and holes is inhabited so that more charges are generated to reach the surface of the photocatalyst and therefore improve the photocatalytic degradation efficiency. Moreover, more Fe (II) sites formed on the 5%Fe-Bi4O5Br2 photocatalyst and facilitated the activation of H2O2 to form oxidative species, which greatly enhanced the degradation efficiency of Tetracycline.

Vertical tank capacity measurement based on Monte Carlo method.

Vertical tanks are commonly used appliances for liquids, and its capacity is very important for quantitative liquid ratio and liquid trade. In order to measure the capacity of vertical tanks more conveniently, this paper proposes a vertical tank capacity measurement method based on Monte Carlo Method. The method arranges a plurality of sensor points on the inner surface of the tank, and then performs Monte Carlo tests by generating a large number of random sample points, and finally calculates the capacity by counting the sample points that meet the criterion. The criterion for whether a sample point is located in the tank, which is the core issue, is established with the coordinates of sensor points and the distance between different sensor points along the surface of the tank. The results show that the absolute error of the measurement results of the proposed method does not exceed ±0.0003[m3], and the absolute error of capacity per unit volume has a linear relationship with the height of the vertical tank, and has little effect with the radial size of the vertical tank.

Sufentanil postoperative analgesia reduce the increase of T helper 17 (Th17) cells and FoxP3+ regulatory T (Treg) cells in rat hepatocellular carcinoma surgical model: A randomised animal study.

BACKGROUND: Surgery-related pain and opioids might exacerbate immune defenses in immunocompromised cancer patients which might affect postoperativd overall survival. Sufentanil is a good postoperative pain control drug,the present study aimed to figure out whether it effect T cell immunity in rat hepatocellular carcinoma surgical model. METHODS: A rat hepatocellular carcinoma (HCC) models was established by N-nitrosodiethylamine. Forty-eight of them were randomly divided into 3 equal groups: surgery without postoperative analgesia (Group C), surgery with morphine postoperative analgesia (Group M), surgery with sufentanil postoperative analgesia (Group S). Each animal underwent a standard left hepatolobectomy, and intraperitoneally implanted with osmotic minipumps filled with sufentanil, morphine or normal saline according to the different group. The food and water consumptions, body weight changes, locomotor activity and mechanical pain threshold (MPT) were observed. The ratio of CD4+/CD8+, proportions of Th1, Th2, Th17 and Treg cells in blood were detected using flow cytometry. The liver function and the rats' survival situation of each group were observed. RESULTS: The food and water consumption, locomotor activity and MPT of group C declined than those of group S and M on d1, d2, d3 (P < 0.05). The CD4+/CD8+ ratio and the proportion of Th1 cells were significantly higher while the proportion of Th2, Th17 and Treg cells were significantly lower in group S and group M compared with group C. The rats of group S have higher CD4+/CD8+ ratio on d3, while lower proportion of Treg cells on d7 compared with group M. The plasma ALT and AST values in group C were significantly higher than that of group S and group M on both d3 and d7. There were not significant differences in mortality rate between 3 groups. CONCLUSIONS: Sufentanil and morphine postoperative analgesia in HCC rats accepted hepatectomy could relieve postoperative pain, promote the recovery of liver function after surgery, alleviate the immunosuppressive effect of pain. Furthermore, Compared to morphine, sufentanil might have a slighter effect on CD4+/CD8+ ratio and Treg frequencies. Therefore, sufentanil postoperative analgesia is better than morphine in HCC hepatectomy rats.

Visible-near-infrared-responsive g-C3N4Hx+ reduced decatungstate with excellent performance for photocatalytic removal of petroleum hydrocarbon.

The development of photocatalysts making full use of natural light sources is highly desired for the remediation of marine oil spill pollution, which is full of challenges. Herein, we demonstrate a well-defined visible-near-infrared-responsive g-C3N4Hx+ reduced decatungstate charge-transfer salt (RCD-CTS), which possess efficient light-absorption ability ranging from visible light to the near infrared region. The RCD-CTS photocatalyst exhibits excellent performance for photocatalytic removal of petroleum hydrocarbon. The structural characterization and theoretical calculation confirmed strong chemical interaction between components and partly reduction of decatungstate results in the plasmonic properties and the absorption of near infrared light. As a results, it is proposed that"hot electrons"transfer process generated by plasmon effect promotes the efficient separation of charge-carriers. Ultimately, this work sheds light on the discovery and application of visible-near-infrared-responsive optical materials that may be exploited further in artificial photosynthesis, solar energy conversion, and phototherapy.

Construction of an Inducible CRISPR/Cas9 System for CXCR4 Gene and Demonstration of its Effects on MKN-45 Cells.

The CRISPR/Cas9 system is an effective tool for gene editing. However, this conventional expression system cannot control the timing of gene editing and does not utilize resistance screening markers. Therefore, carrying out CRISPR/Cas9 experiments is extremely inconvenient. Our aim is to develop an inducible lentiviral vector-based gene-editing system for C-X-C chemokine receptor 4 (CXCR4) by CRISPR/Cas9, and to demonstrate its function in MKN-45 cell. The DNA fragments of Blasticidin and T2A-GFP were produced using the lenti-Cas9-BLAST and PX458 plasmids as templates. The PCR products were harvested and cloned into the lenti-guide-puro plasmid to yield the lenti-guide-BLAST-GFP plasmid. Three double-stranded guide RNA (gRNA) sequences targeting the exon 2 of CXCR4 gene were designed online (http://crispr.mit.edu), synthesized, and recombined into the lenti-guide-BLAST-GFP plasmid, to yield the lenti-guide-BLAST-GFP-gRNA plasmid. The pCW-Cas9 and lenti-guide-BLAST-GFP-gRNA plasmids were packaged with lentiviral vectors, which were then transfected into MKN-45 cells, to identify the CXCR4 gene-editing effects using the T7 endonuclease 1 (T7E1) and Western blot assays. The lenti-guide-BLAST-GFP and lenti-guide-BLAST-GFP-gRNA plasmids were successfully constructed and packaged, to yield lentiviral particles. Transfection of the pCW-Cas9 and lenti-guide-BLAST-GFP-gRNA viral vectors could decrease the expression of CXCR4 protein, and lead to gene editing in MKN-45 cells. The efficiencies of gRNA-1, gRNA-2, and gRNA-3 were 45.6%, 53.6%, and 56.7%, respectively. Furthermore, the chemotactic efficiency of the dual viral vector-infected MKN-45 cells was significantly decreased in response to SDF-1. The numbers of migratory cells in the lower chamber of the transwell system were 30.0 ± 0.23, 29.7 ± 1.55, 28.2 ± 1.11 and 36.1 ± 2.00 cells per field (400×) for gRNA-1, gRNA-2, gRNA-3 and the control, respectively (P < 0.05). We constructed an inducible CXCR4 gene-editing, dual-vector CRISPR/Cas9 system, which could induce CXCR4 gene editing in MKN-45 cells in a doxycycline-dependent manner and thus reduce the migration of MKN-45 cells.

The stromal cell-derived factor 1/C-X-C chemokine receptor type 4 axis is important in neutrophil migration caused by cardiopulmonary bypass in children.

OBJECTIVES: Acute lung injury caused by cardiopulmonary bypass (CPB) is characterized by massive neutrophil migration to the lungs. Neutrophil migration may be closely related to stromal cell-derived factor 1 (SDF-1)/C-X-C chemokine receptor Type 4 (CXCR4) axis activation, which plays an essential role in modulating the trafficking of neutrophils. We investigated the changes in the expression of SDF-1/CXCR4 axis components before and after CPB as well as the role of the axis in driving the migration of neutrophils in patients with congenital heart disease. METHODS: Fifteen children undergoing elective open-heart surgery under CPB (CPB group) and 15 children undergoing minimally invasive ultrasound-guided closure of a ventricular septal defect (control group) were enrolled in this non-randomized clinical trial. Neutrophil CXCR4 expression was evaluated using quantitative reverse transcription polymerase chain reaction and flow cytometry. An enzyme-linked immunosorbent assay was used to measure plasma SDF-1 levels. The migration characteristics of neutrophils under 8 different combinations designated A-H were assayed with and without a specific CXCR4 antagonist, AMD3100, to evaluate the functional significance of the SDF-1/CXCR4 axis. RESULTS: Both CXCR4 gene and protein expressions were elevated in the CPB group compared with the control group after CPB (0.81 ± 0.55 vs 1.76 ± 1.32; P < 0.05, 1.96 ± 0.86 vs 2.65 ± 0.79; P < 0.05), and plasma SDF-1 levels were also increased in the former compared with the latter (197.84 ± 19.96 pg/ml vs 539.13 ± 99.83 pg/ml; P < 0.05). The in vitro experiments showed that plasma isolated post-CPB exhibited the strongest chemotactic effect on neutrophils. The CPB group showed a higher chemotaxis index, which serves as a marker for the effects of plasma on neutrophils, than that for the control group after CPB (37.38 ± 9.39 vs 13.61 ± 2.59; P < 0.05). In addition, the CXCR4 antagonist AMD3100 significantly abrogated the increase in neutrophil migration in the CPB group. CONCLUSIONS: Exposure to CPB, which activates the SDF-1/CXCR4 axis, using an antagonist to prevent neutrophil trafficking, may be a beneficial therapy for the related complications.

Roux-en-Y gastric bypass improves glucose homeostasis, reduces oxidative stress and inflammation in livers of obese rats and in Kupffer cells via an AMPK-dependent pathway.

BACKGROUND: Oxidative stress and inflammation are implicated in the pathogenesis of steatohepatitis. We hypothesize that Roux-en-Y gastric bypass reduces oxidative stress and inflammation in the liver of obese rats via activation of AMPK-α. METHODS: Obese Sprague-Dawley male rats underwent either sham operation or Roux-en-Y gastric bypass. Hepatic TNF-α, NF-κB, IRS-2, PI3 kinase, PKC-ζ, NOX2, and AMPK-α were measured. Mechanistic studies were done in a rat Kupffer cell line (RKC1) that was treated with free fatty acids to mimic lipotoxicity and then transfected with AMPK-α siRNA. Reactive oxygen species, TNF-α, NF-κB, AMPK-α, p-AMPK-α, PPAR-γ, and NOX2 were measured. A t test was used. RESULTS: Roux-en-Y gastric bypass lowered nonfasting serum glucose, improved the glucose tolerance test, and induced IRS2/PI3 kinase interaction. Additionally, Roux-en-Y gastric bypass decreased hepatic NOX2, PKC-ζ, TNF-α expression and activation of NF-κB. Free fatty acids increased reactive oxygen species, TNF-α protein, NOX2 protein, and activated NF-κB. Rosiglitazone attenuated the free fatty acids-induced increase in reactive oxygen species, TNF-α, NOX2, and NF-κB; blocking AMPK-α by siRNA abolished the effects of rosiglitazone. CONCLUSION: Roux-en-Y gastric bypass exhibits antidiabetic properties and is associated with downregulation of proinflammation genes and oxidative stress in the liver and within Kupffer cells via activation of AMPK-α.