Analysis of factors influencing the determination of indications for allergen-specific immunotherapy.

OBJECTIVE: To develop a questionnaire and a scoring system for evaluating physicians' knowledge of allergen immunotherapy (AIT). METHODS: Questionnaire was designed using the Questionnaire Star tool. A total of 1024 physicians were assessed, and based on the score divided into accurate judgment and inaccurate judgment groups. Statistical analysis was done, and counting data were expressed as frequencies and percentage values. Chi-square test and multi-factor logistic analysis were used to determine influencing factors on the indications for AIT. RESULTS: Physician's age, grade of the hospital, and pediatric specialty influenced the accurate judgment of AIT indication after adjustment for independent variables (P < 0.05). In all, 80.5% physicians exercised accurate assessment for allergic rhinitis. Allergic conjunctivitis was judged accurately by 47.0% physicians. Bronchial asthma was judged accurately by 71.0% physicians, and atopic dermatitis by 61.3% physicians, with a higher accuracy rate for pediatricians than nonpediatricians for all the mentioned conditions (P < 0.05). There was no significant difference in the accuracy of judgment between pediatricians and non-pediatricians in terms of AIT for food allergy and dust mite sensitization (P > 0.05). CONCLUSION: The results of our study demonstrated a high accuracy judgment rate among clinicians for rhinitis, asthma, and dermatitis, and a low accuracy rate for desensitization of healthy people with allergic conjunctivitis, food allergies, and allergen sensitization.

Analysis of factors influencing the determination of indications for allergen-specific immunotherapy

Objective: To develop a questionnaire and a scoring system for evaluating physicians’ knowledge of allergen immunotherapy (AIT). Methods: Questionnaire was designed using the Questionnaire Star tool. A total of 1024 physicians were assessed, and based on the score divided into accurate judgment and inaccurate judgment groups. Statistical analysis was done, and counting data were expressed as frequencies and percentage values. Chi-square test and multi-factor logistic analysis were used to determine influencing factors on the indications for AIT. Results: Physician’s age, grade of the hospital, and pediatric specialty influenced the accurate judgment of AIT indication after adjustment for independent variables (P < 0.05). In all, 80.5% physicians exercised accurate assessment for allergic rhinitis. Allergic conjunctivitis was judged accurately by 47.0% physicians. Bronchial asthma was judged accurately by 71.0% physicians, and atopic dermatitis by 61.3% physicians, with a higher accuracy rate for pediatricians than nonpediatricians for all the mentioned conditions (P < 0.05). There was no significant difference in the accuracy of judgment between pediatricians and non-pediatricians in terms of AIT for food allergy and dust mite sensitization (P > 0.05). Conclusion: The results of our study demonstrated a high accuracy judgment rate among clinicians for rhinitis, asthma, and dermatitis, and a low accuracy rate for desensitization of healthy people with allergic conjunctivitis, food allergies, and allergen sensitization (AU)

A Novel Regulation Strategy of Solid Electrolyte Interphase Based on Anion-Solvent Coordination for Magnesium Metal Anode.

Magnesium (Mg) metal anode is a highly desirable candidate among various high energy density metal anodes, possessing higher volumetric capacity and better safety characteristic compared to lithium metal. However, most Mg salts in conventional Mg electrolytes easily react with Mg metal to form blocking layers, leading to inferior reversibility of Mg plating/stripping. Here, a stable Mg2+ -conducting solid electrolyte interphase (SEI) is successfully constructed on Mg metal anode by regulating the molecular-orbital-energy-level toward an aluminum(III)-centered anion Mg salt through anion-solvent coordination. Of which, the LUMO energy level of perfluorinated pinacolatoaluminate (Al(O2 C2 (CF3 )4 )2 - , abbreviated as FPA) anion has been adjusted by coordinating with solvent molecule (tetrahydrofuran) for facilitating the formation of advantageous SEI. The existence of SEI formed by FPA anion greatly improves the reversibility and long-term stability of Mg plating/stripping process. More importantly, based on this aluminum(III)-centered Mg electrolyte, the Mo6 S8 /Mg batteries can achieve a fantastic cycle performance of 9000 cycles, proving the beneficial effect of SEI on the cycling stability of Mg battery system. These findings open up a promising avenue to construct stable and compatible SEI on Mg metal anode, and lay significant foundations for the successful development of rechargeable Mg metal batteries.

A thermodynamic model for predicting transient pressure evolution in response to venting and vaporization of liquefied gas under sudden release.

Liquefied gases in energy supply chain suffer the risks of disastrous accidents (e.g. boiling liquid expanding vapor explosion) normally resulted from a sudden release. The boiling response and its associated pressure transient under sudden release determine the severity of the accident, and are crucial for assessing the consequences of the sudden release. For predicting the pressure transient, a thermodynamic model of the liquefied gas under sudden release is presented in this paper. A three-stage modelling approach is proposed to describe the entire thermodynamic process after sudden release according to the venting and boiling behaviors of liquefied gas. A set of differential-algebraic equations are established based on mass and energy conservation for predicting the transient thermodynamic parameters. Comparisons of model predictions with experimental data show a consistent trend in pressure-time histories, with relative deviations of average pressures less than 5.78 %. The results show that the minimum pressure point has a time delay compared to the boiling inception point. The increase of release pressure and the decrease of vessel scale will strengthen the pressure rebound, and the increase of vent area will lead to higher depressurization and re-pressurization rate.

Suppression effects of micro-fin surface on the explosive boiling of liquefied gas under rapid depressurization.

The boiling liquid expanding vapor explosion (BLEVE) is a most severe hazard in liquefied gas storage and transportation, and its prevention depends on the suppression of the explosive boiling during tank depressurization. This paper proposes an idea of using micro-fin type surface to suppress the explosive boiling, and experimentally investigates the suppression mechanisms and quantitative effects on the explosive boiling. In the experiments, the bubble behaviors on a micro-fin and a smooth surface are observed for phenomenal analysis, and the explosive boiling consequences of the two surfaces are measured for quantitative evaluation. The results show that, the micro-fin surface brings forward the nucleation onset and reduces the boiling region, resulting in a weakened explosive boiling process. Among release pressures of 200 kPa-500 kPa and vent areas of 1.8 cm2-5.3 cm2, the adopted micro-fin surface reduces the boiling-induced pressure rise and the released energy by up to 24.5% and 35.6%, respectively.

Efficacy of intracellular immune checkpoint-silenced DC vaccine.

BACKGROUND: DC-based tumor vaccines have had limited clinical success thus far. SOCS1, a key inhibitor of inflammatory cytokine signaling, is an immune checkpoint regulator that limits DC immunopotency. METHODS: We generated a genetically modified DC (gmDC) vaccine to perform immunotherapy. The adenovirus (Ad-siSSF) delivers two tumor-associated antigens (TAAs), survivin and MUC1; secretory bacterial flagellin for DC maturation; and an RNA interference moiety to suppress SOCS1. A 2-stage phase I trial was performed for patients with relapsed acute leukemia after allogenic hematopoietic stem cell transplantation: in stage 1, we compared the safety and efficacy between gmDC treatment (23 patients) and standard donor lymphocyte infusion (25 patients); in stage 2, we tested the efficacy of the gmDC vaccine for 12 acute myeloid leukemia (AML) patients with early molecular relapse. RESULTS: gmDCs elicited potent TAA-specific CTL responses in vitro, and the immunostimulatory activity of gmDC vaccination was demonstrated in rhesus monkeys. A stage 1 study established that this combinatory gmDC vaccine is safe in acute leukemia patients and yielded improved survival rate. In stage 2, we observed a complete remission rate of 83% in 12 relapsed AML patients. Overall, no grade 3 or grade 4 graft-versus-host disease incidence was detected in any of the 35 patients enrolled. CONCLUSIONS: This study, with combinatory modifications in DCs, demonstrates the safety and efficacy of SOCS1-silenced DCs in treating relapsed acute leukemia. TRIAL REGISTRATION: ClinicalTrials.gov NCT01956630. FUNDING: National Institute of Health (R01CA90427); the Key New Drug Development and Manufacturing Program of the "Twelfth Five-Year Plan" of China (2011ZX09102-001-29); and Clinical Application Research of Beijing (Z131107002213148).

Two Players Make a Formidable Combination: In Situ Generated Poly(acrylic anhydride-2-methyl-acrylic acid-2-oxirane-ethyl ester-methyl methacrylate) Cross-Linking Gel Polymer Electrolyte toward 5 V High-Voltage Batteries.

Electrochemical performance of high-voltage lithium batteries with high energy density is limited because of the electrolyte instability and the electrode/electrolyte interfacial reactivity. Hence, a cross-linking polymer network of poly(acrylic anhydride-2-methyl-acrylic acid-2-oxirane-ethyl ester-methyl methacrylate) (PAMM)-based electrolyte was introduced via in situ polymerization inspired by "shuangjian hebi", which is a statement in a traditional Chinese Kungfu story similar to the synergetic effect of 1 + 1 > 2. A poly(acrylic anhydride) and poly(methyl methacrylate)-based system is very promising as electrolyte materials for lithium-ion batteries, in which the anhydride and acrylate groups can provide high voltage resistance and fast ionic conductivity, respectively. As a result, the cross-linking PAMM-based electrolyte possesses a significant comprehensive enhancement, including electrochemical stability window exceeding 5 V vs Li+/Li, an ionic conductivity of 6.79 × 10-4 S cm-1 at room temperature, high mechanical strength (27.5 MPa), good flame resistance, and excellent interface compatibility with Li metal. It is also demonstrated that this gel polymer electrolyte suppresses the negative effect resulting from dissolution of Mn2+ ions at 25 and 55 °C. Thus, the LiNi0.5Mn1.5O4/Li and LiNi0.5Mn1.5O4/Li4Ti5O12 cells using the optimized in situ polymerized cross-linking PAMM-based gel polymer electrolyte deliver stable charging/discharging profiles and excellent rate performance at room temperature and even at 55 °C. These findings suggest that the cross-linking PAMM is an intriguing candidate for 5 V class high-voltage gel polymer electrolyte toward high-energy lithium-on batteries.

In Situ Formation of Polysulfonamide Supported Poly(ethylene glycol) Divinyl Ether Based Polymer Electrolyte toward Monolithic Sodium Ion Batteries.

Sodium ion battery is one of the promising rechargeable batteries due to the low-cost and abundant sodium sources. In this work, a monolithic sodium ion battery based on a Na3 V2 (PO4 )3 cathode, MoS2 layered anode, and polyether-based polymer electrolyte is reported. In addition, a new kind of polysulfonamide-supported poly(ethylene glycol) divinyl ether based polymer electrolyte is also demonstrated for monolithic sodium ion battery via in situ preparation. The resultant polymer electrolyte exhibits relatively high ionic conductivity (1.2 mS cm-1 ) at ambient temperature, wide electrochemical window (4.7 V), and favorable mechanical strength (25 MPa). Moreover, such a monolithic Na3 V2 (PO4 )3 /MoS2 sodium ion battery using this polymer electrolyte delivers outstanding rate capability (up to 10 C) and superior cyclic stability (84%) after 1000 cycles at 0.5 C. What is more essential, such a polymer electrolyte based soft-package monolithic sodium ion cell can still power a red light emitting diode lamp and run finite times without suffering from any internal short-circuit failures, even in the case of a bended and wrinkled state. Considering these aspects, this work no doubt provides a new approach for the design of a high-performance polymer electrolyte toward monolithic sodium ion battery with exceptional rate capability and high safety.

Radical-mediated divergent cyclization of benzamides toward perfluorinated or cyanated isoquinolinediones.

A simple and efficient copper-controlled divergent cyclization of benzamides, which leads to perfluorinated or cyanated isoquinolinediones, is developed. In the presence of AIBN, methacryloyl benzamides with perfluoroalkyl iodides undergo cascade radical addition/cyclization to afford perfluoroinated isoquinolinediones as the major product under metal-free conditions, whereas the use of CuI (10 mol%) is able to redirect the cyclization to yield isoquinolinediones bearing an α-cyano quaternary carbon center. The cyclization features controllable divergent synthesis and a broad substrate scope as well as highly practical reaction conditions, thereby making this strategy a highly attractive means to fluorinate or cyanate isoquinolinediones.

[Key Preparation Technique and Clinical Application of Frozen Platelets].

OBJECTIVE: To explore the key technique for preparation of the frozen platelet and efficacy of its clinical application. METHODS: The influences of the donators' peripheral platelet count, starting time of freeze, injection rate and evenness of the freeze-protective agent, storage mode, re-melting temperature and the capacity of water-bath etc. on the quality of the frozen platelets were analyzed retrospectively in 3 257 samples of frozen platelets before platelet pheresis. Then, the platelet counts were examined in 150 cases transfused with frozen platelets at the time-points of 1, 24, 48 and 72 hrs after transfusion, 90 cases suffered from the obstetrical bleeding were transfused with 200 parts of the re-melting frozen platelets, and then the peripheral blood platelet count, platelet increasing index(CCI), bleeding time and blood clot retraction rate etc. were observed for determining the clinical efficiency of the frozen platelets. RESULTS: The floccule in the re-melting frozen platelets from the donators with (175-250)×10(9)/L platelets were decreased significantly(P<0.01). The quality of frozen platelets was influenced by the following factors, such as injection of DMSO at a too fast and heterogeneous rate, blood bags stored in a multilamminar space, and re-melting in a water-bath of small capacity etc. The routine storage for 0 and 3 days did not influence the quality of the frozen platelets. The recovery rate of one year-freezing platelets all was higher than 80%. The effects of the frozen platelets transfused into the patients with obstetrical bleeding displayed good haemostatic results, and the blood transfusion reaction did not occur. However, the frozen platelets immediately were exhausted and displayed their function, but the counting after 48 hrs could not display a good effect of raising platelet number. CONCLUSIONS: The peripheral platelet count before platelet pheresis, the injection rate and evenness of the protective agent, the number of stratum for blood bags and the capacity of re-melting water-bath etc. all are the key factors influencing the quality of the frozen platelets. The frozen platelets prepared in this study shows a good efficacy of clinical application.

Allicin inhibits oxidative stress-induced mitochondrial dysfunction and apoptosis by promoting PI3K/AKT and CREB/ERK signaling in osteoblast cells.

Osteoporosis is a disease of the skeleton that is characterized by the loss of bone mass and degeneration of bone microstructure, resulting in an increased risk of fracture. Oxidative stress, which is known to promote oxidative damage to mitochondrial function and also cell apoptosis, has been recently indicated to be implicated in osteoporosis. However, there are few agents that counteract oxidative stress in osteoporosis. In the present study, the protective effects of allicin against the oxidative stress-induced mitochondrial dysfunction and apoptosis were investigated in murine osteoblast-like MC3T3-E1 cells. The results demonstrated that allicin counteracted the reduction of cell viability and induction of apoptosis caused by hydrogen peroxide (H2O2) exposure. The inhibition of apoptosis by allicin was confirmed by the inhibition of H2O2-induced cytochrome c release and caspase-3 activation. Moreover, the inhibition of apoptosis by allicin was identified to be associated with the counteraction of H2O2-induced mitochondrial dysfunction. In addition, allicin was demonstrated to be able to significantly ameliorate the repressed phosphoinositide 3-kinase (PI3K)/AKT and cyclic adenosine monophosphate response element-binding protein (CREB)/extracellular-signal-regulated kinase (ERK) signaling pathways by H2O2, which may also be associated with the anti-oxidative stress effects of allicin. In conclusion, allicin protects osteoblasts from H2O2-induced oxidative stress and apoptosis in MC3T3-E1 cells by improving mitochondrial function and the activation of PI3K/AKT and CREB/ERK signaling. The present study implies a promising role of allicin in oxidative stress-associated osteoporosis.

Adoptive transfer of T cells transduced with a chimeric antigen receptor to treat relapsed or refractory acute leukemia: efficacy and feasibility of immunotherapy approaches.

Treatment outcomes of acute leukemia (AL) have not improved over the past several decades and relapse rates remain high despite the availability of aggressive therapies. Conventional relapsed leukemia treatment includes second allogeneic hematopoietic stem cell transplantation (allo-HSCT) and donor lymphocyte infusion (DLI), which in most cases mediate, at best, a modest graft-versus-leukemia effect, although their clinical efficacy is still limited. Although allo-HSCT following myeloablative conditioning is a curative treatment option for younger patients with acute myeloid leukemia (AML) in a first complete remission (CR), allo-HSCT as a clinical treatment is usually limited because of treatment-related toxicity. The overall DLI remission rate is only 15%-42% and 2-year overall survival (OS) is approximately 15%-20%, with a high (40%-60%) incidence of DLI-related graft-versus-host disease (GVHD). Therefore, development of new, targeted treatment strategies for relapsed and refractory AL patients is ongoing. Adoptive transfer of T cells with genetically engineered chimeric antigen receptors (CARs) is an encouraging approach for treating hematological malignancies. These T cells are capable of selectively recognizing tumor-associated antigens and may overcome many limitations of conventional therapies, inducing remission in patients with chemotherapy-refractory or relapsed AL. In this review, we aimed to highlight the current understanding of this promising treatment modality, discussing its adverse effects and efficacy.

Synthesis of Perfluorinated Isoquinolinediones through Visible-Light-Induced Cyclization of Alkenes.

A novel visible-light-induced carboperfluoroalkylation of alkenes using perfluoroalkyl iodides and bromides as Rf sources, leading to isoquinoline-1,3-diones, was developed. This method offers rapid entry to perfluorinated isoquinoline-1,3(2H,4H)-diones from N-alkyl-N-methacryloyl benzamides under mild reaction conditions, allowing for the incorporation of a wide variety of perfluorinated groups such as CF3, C3F7, C4F9, C6F13, C8F17, C10F21, and CF2CO2Et.

Anterior arthroscopic-assisted fixation of posterior cruciate ligament avulsion fractures.

BACKGROUND: Avulsion fractures of the tibial insertion of the posterior cruciate ligament (PCL) have always been regarded as rare injuries. The tibial attachment of the PCL is located in an area, which is difficult to access. HYPOTHESIS: To verify the effects of anterior arthroscopic fixation of PCL avulsion fractures. METHODS: 18 patients with PCL avulsion fracture were included. The inclusion criteria were: (1) the fracture fragment size was greater than 20 mm; (2) surgery in the acute phase of fractures (<3 weeks). The intervention was anterior arthroscopic fixation of fractures. Outcome variables included posterior laxity assessment with KT2000 arthrometer, posterior sag sign, the quadriceps activation test, the reverse Lachman, posterior stress X-rays, range of motion, and the IKDC form assessment. RESULTS: Complete osseous union showed in all cases during the follow-up (24-49 months). The posterior laxity assessment demonstrated slight posterior tibia translation (<5 mm) on the femur in 1 patient at 89 N and in 2 at maximal testing. All were stable on the posterior sag sign, the quadriceps activation test, the reverse Lachman and posterior stress X-rays. Two had loss of flexion of about 10° (grade B). Others showed a full range of knee motion. According to the IKDC form assessment, 16 patients were classified as grade A and 2 were classified as grade B. 16 of 18 patients were absolutely pain free, and there was general satisfaction on pain questionnaire. All the patients returned to their pre-injury knee function. No revision surgery was performed. CONCLUSIONS: The anterior arthroscopic-assisted fixation guided with a tibial PCL guide is a simple and feasible alternative for treating PCL avulsion fractures when the fragment size is larger than 20 mm.

Protein kinase C promotes cardiac fibrosis and heart failure by modulating galectin-3 expression.

Protein kinase C (PKC) and galectin-3 are two important mediators that play a key pathogenic role in cardiac hypertrophy and heart failure (HF). However, the molecular mechanisms and signaling pathways are not fully understood. In this study, we explored the relationship between and roles of PKC-α and galectin-3 in the development of HF. We found that activation of PKC by phorbol dibutyrate (PDB) increased galectin-3 expression by ~180%, as well as collagen I and fibronection accumulation in cultured HL-1 cardiomyocytes. Over-expression of galectin-3 in HL-1 cells increased collagen I protein production. Inhibition of galectin-3 by ß-lactose blocked PDB-induced galectin-3 and collagen production, indicating that galectin-3 mediates PKC-induced cardiac fibrosis. In rats subjected to pulmonary artery banding (PAB) to induce right ventricular HF, galectin-3 was increased by ~140% in the right ventricle and also by ~240% in left ventricle compared to control. The elevated galectin-3 is consistent with an increase of total and activated (phosphorylated) PKC-α, α-SMA and collagen I. Finally, we extended our findings to examine the role of angiotensin II (Ang II), which activates the PKC pathway and contributes to cardiac fibrosis and the development of HF. We found that Ang II activated the PKC-α pathway and increased galectin-3 expression and collagen production. This study provides a new insight into the molecular mechanisms of HF mediated by PKC-α and galectin-3. PKC-α promotes cardiac fibrosis and HF by stimulation of galectin-3 expression.

Taichi-inspired rigid-flexible coupling cellulose-supported solid polymer electrolyte for high-performance lithium batteries.

Inspired by Taichi, we proposed rigid-flexible coupling concept and herein developed a highly promising solid polymer electrolyte comprised of poly (ethylene oxide), poly (cyano acrylate), lithium bis(oxalate)borate and robust cellulose nonwoven. Our investigation revealed that this new class solid polymer electrolyte possessed comprehensive properties in high mechanical integrity strength, sufficient ionic conductivity (3 × 10(-4) S cm(-1)) at 60°C and improved dimensional thermostability (up to 160°C). In addition, the lithium iron phosphate (LiFePO4)/lithium (Li) cell using such solid polymer electrolyte displayed superior rate capacity (up to 6 C) and stable cycle performance at 80°C. Furthermore, the LiFePO4/Li battery could also operate very well even at an elevated temperature of 160°C, thus improving enhanced safety performance of lithium batteries. The use of this solid polymer electrolyte mitigates the safety risk and widens the operation temperature range of lithium batteries. Thus, this fascinating study demonstrates a proof of concept of the use of rigid-flexible coupling solid polymer electrolyte toward practical lithium battery applications with improved reliability and safety.

Clinical research of genetically modified dendritic cells in combination with cytokine-induced killer cell treatment in advanced renal cancer.

BACKGROUND: Renal cell carcinoma (RCC) is a malignant disease that demonstrates resistance to standard chemotherapeutic agents. Yet Active immunization using genetically modified dendritic cells holds promise for the adjuvant treatment of malignancies to eradicate or control residual disease. Cytokine-induced killer (CIK) cells are a heterogeneous population of effector CD8+ T cells with diverse TCR specificities, possessing non-MHC-restricted cytolytic activities against tumor cells. Clinical studies have confirmed benefit and safety of CIK cell-based therapy for patients with malignancies. This clinical trial was conducted to evaluate efficacy and safety of genetically modified dendritic cells in combination with Cytokine-Induced Killer Cell (gmDCs-CIK) treatment of patients with RCC. METHODS: 28 patients with advanced renal cancer were admitted to Affiliated Hospital of Academy of Military Medical Sciences from December 2010 to March 2012 and treated by gmDCs-CIK. Clinical efficacy and safety between pre- and post-treatment were compared. RESULTS: This analysis showed an objective response rate (ORR) of 39% and a disease control rate (DCR) of as 75%. There is no significant relationship between clinical efficacy and whether metastasis occurred or not (P > 0.05). There is no significant relationship between ORR and cycles of treatment (P > 0.05), but DCR was significantly related with cycles of treatment (P < 0.05). No clinically significant side effects were observed. There were no significant changes of T cell subsets including CD3+, CD4+, CD8+, CD4+ CD25+ Treg cells except Th1 in peripheral blood between day 30 after immunotherapy and 1 day before immunotherapy in 11 patients. CONCLUSION: DC-CIK is feasible and effective in treating advanced renal cancer and thus provides a new approach. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01924156. Registration date: August 14, 2013.

Sustainable, heat-resistant and flame-retardant cellulose-based composite separator for high-performance lithium ion battery.

A sustainable, heat-resistant and flame-retardant cellulose-based composite nonwoven has been successfully fabricated and explored its potential application for promising separator of high-performance lithium ion battery. It was demonstrated that this flame-retardant cellulose-based composite separator possessed good flame retardancy, superior heat tolerance and proper mechanical strength. As compared to the commercialized polypropylene (PP) separator, such composite separator presented improved electrolyte uptake, better interface stability and enhanced ionic conductivity. In addition, the lithium cobalt oxide (LiCoO2)/graphite cell using this composite separator exhibited better rate capability and cycling retention than that for PP separator owing to its facile ion transport and excellent interfacial compatibility. Furthermore, the lithium iron phosphate (LiFePO4)/lithium cell with such composite separator delivered stable cycling performance and thermal dimensional stability even at an elevated temperature of 120°C. All these fascinating characteristics would boost the application of this composite separator for high-performance lithium ion battery.

Insulin ameliorates miR-1-induced injury in H9c2 cells under oxidative stress via Akt activation.

Growing evidence indicates that aberrant upregulation of microRNA-1 (miR-1) occurs in ischemic myocardium. In addition, insulin elicits metabolism-independent cardioprotection against cardiovascular diseases. The aim of this study is to determine whether insulin ameliorates miR-1-induced injury in H9c2 cells under oxidative stress and to investigate the underlying mechanisms. By quantitative real-time RT-PCR (qRT-PCR), we show that miR-1 is upregulated in H9c2 cells after treatment with hydrogen peroxide (H(2)O(2)), and this effect is both dose- and time dependent. Furthermore, expression of miR-1 decreased significantly after insulin treatment (4.5 ± 0.1 vs. 3.0 ± 0.2, p < 0.05). To determine the potential role of miR-1 in cellular injury and gene regulation, adenovirus-mediated overexpression of miR-1 was used. Overexpression of miR-1 decreased cell viability by 28 ± 2 % (n = 6, p < 0.05) and damaged Akt activation with or without H(2)O(2) treatment. To further investigate the effect of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in miR-1-induced injury, H9c2 cells were pretreated with LY294002 (10 µM LY, a specific inhibitor of PI3K) with or without insulin (100 nM) and subjected to H(2)O(2) treatment. LY pretreatment-inhibited Akt activation, lead to increased reactive oxygen species (ROS), and further decreased cell viability induced by miR-1 (n = 6, p < 0.05, n = 9-10 cells/group, p < 0.05 and n = 6, p < 0.05) under oxidative stress. This effect was abolished by insulin. In summary, our findings suggest that miR-1 expression is sensitive to H(2)O(2) stimulation. In addition, insulin decreases miR-1 expression and induces a marked protective effect on miR-1-induced injury under oxidative stress, which may be mediated by the Akt-mediated pathway. These results provide an important, novel clue as to the mechanism of the cardiovascular action of insulin.

Cardioprotection from oxidative stress in the newborn heart by activation of PPARγ is mediated by catalase.

Regulation of catalase (CAT) by peroxisome proliferator-activated receptor-γ (PPARγ) was investigated to determine if PPARγ activation provides cardioprotection from oxidative stress caused by hydrogen peroxide (H(2)O(2)) in an age-dependent manner. Left ventricular developed pressure (LVDP) was measured in Langendorff perfused newborn or adult rabbit hearts, exposed to 200µM H(2)O(2), with perfusion of rosiglitazone (RGZ) or pioglitazone (PGZ), PPARγ agonists. We found: (1) H(2)O(2) significantly decreased sarcomere shortening in newborn ventricular cells but not in adult cells. Lactate dehydrogenase (LDH) release occurred earlier in newborn than in adult heart, which may be due, in part, to the lower expression of CAT in newborn heart. (2) RGZ increased CAT mRNA and protein as well as activity in newborn but not in adult heart. GW9662 (PPARγ blocker) eliminated the increased CAT mRNA by RGZ. (3) In newborn heart, RGZ and PGZ treatment inhibited release of LDH in response to H(2)O(2) compared to H(2)O(2) alone. GW9662 decreased this inhibition. (4) LVDP was significantly higher in both RGZ+H(2)O(2) and PGZ+H(2)O(2) groups than in the H(2)O(2) group. Block of PPARγ abolished this effect. In contrast, there was no effect of RGZ in adult. (5) The cardioprotective effects of RGZ were abolished by inhibition of CAT. In conclusion, PPARγ activation is cardioprotective to H(2)O(2)-induced stress in the newborn heart by upregulation of catalase. These data suggest that PPARγ activation may be an effective therapy for the young cardiac patient.