Testosterone promotes the migration, invasion and EMT process of papillary thyroid carcinoma by up-regulating Tnnt1

PURPOSE

To explore the key genes and molecular pathways in the progression of thyroid papillary carcinoma (PTC) promoted by testosterone using RNA-sequencing technology, and to provide new drug targets for improving the therapeutic effect of PTC.

METHODS

Orchiectomy (ORX) was carried out to construct ORX mouse models. TPC-1 cells were subcutaneously injected for PTC formation in mice, and the tumor tissues were collected for RNA-seq. The key genes were screened by bioinformatics technology. Tnnt1 expression in PTC cells was knocked down or overexpressed by transfection. Cell counting kit-8 (CCK-8), colony formation assay, scratch assay and transwell assay were adopted, respectively, for the detection of cell proliferation, colony formation, migration and invasion. Besides, quantification real-time polymerase chain reaction (qRT-PCR) and western blot were utilized to determine the mRNA and protein expression levels of genes in tissues or cells.

RESULTS

Both estradiol and testosterone promoted the growth of PTC xenografts. The key gene Tnnt1 was screened and obtained by bioinformatics technology. Functional analysis revealed that overexpression of Tnnt1 could markedly promote the proliferation, colony formation, migration, invasion, and epithelial-to-mesenchymal transition (EMT) process of PTC cells, as well as could activate p38/JNK pathway. In addition, si-Tnt1 was able to inhibit the cancer-promoting effect of testosterone.

CONCLUSION

Based on the outcomes of bioinformatics and basic experiments, it is found that testosterone can promote malignant behaviors such as growth, migration, invasion and EMT process of PTC by up-regulating Tnnt1 expression. In addition, the function of testosterone may be achieved by activating p38/JNK signaling pathway.

Low-dose exercise protects the heart against established myocardial infarction via IGF-1-upregulated CTRP9 in male mice

Regular exercise is recommended as an important component of therapy for cardiovascular diseases in clinical practice. However, there are still major challenges in prescribing an optimized exercise regimen to individual patients with established cardiac disease. Here, we tested the effects of different exercise doses on cardiac function in mice with established myocardial infarction (MI). Exercise was introduced to mice with MI after 4 weeks of surgery. Low-dose exercise (15 min/day for 8 weeks) improved mortality and cardiac function by increasing 44.39% of ejection fractions while inhibiting fibrosis by decreasing 37.74% of distant region. Unlike higher doses of exercise, low-dose exercise consecutively upregulated cardiac expression of C1q complement/tumor necrosis factor-associated protein 9 (CTRP9) during exercise (>1.5-fold). Cardiac-specific knockdown of CTRP9 abolished the protective effects of low-dose exercise against established MI, while cardiac-specific overexpression of CTRP9 protected the heart against established MI. Mechanistically, low-dose exercise upregulated the transcription factor nuclear receptor subfamily 2 group F member 2 by increasing circulating insulin-like growth factor 1 (IGF-1), therefore, upregulating cardiac CTRP9 expression. These results suggest that low-dose exercise protects the heart against established MI via IGF-1-upregulated CTRP9 and may contribute to the development of optimized exercise prescriptions for patients with MI.

Forkhead box O6 (FoxO6) promotes cardiac pathological remodeling and dysfunction by activating Kif15-TGF-β1 under aggravated afterload

Pathological cardiac hypertrophy exhibits complex and abnormal gene expression patterns and progresses to heart failure. Forkhead box protein O6 (FoxO6) is a key transcription factor involved in many biological processes. This study aimed to explore the role of FoxO6 in cardiac hypertrophy. Three groups of mice were established: wild-type, FoxO6 knockout, and FoxO6-overexpressing. The mice received daily administration of angiotensin-II (Ang-II) or saline for 4 weeks, after which they were examined for cardiac hypertrophy, fibrosis, and function. Elevated cardiac expression of FoxO6 was observed in Ang-II-treated mice. FoxO6 deficiency attenuated contractile dysfunction and cardiac remodeling, including cardiomyocyte hypertrophy and fibroblast proliferation and differentiation. Conversely, FoxO6 overexpression aggravated the cardiomyopathy and heart dysfunction. Further studies identified kinesin family member 15 (Kif15) as downstream molecule of FoxO6. Kif15 inhibition attenuated the aggravating effect of FoxO6 overexpression. In vitro, FoxO6 overexpression increased Kif15 expression in cardiomyocytes and elevated the concentration of transforming growth factor-β1 (TGF-β1) in the medium where fibroblasts were grown, exhibiting increased proliferation and differentiation, while FoxO6 knockdown attenuated this effect. Cardiac-derived FoxO6 promoted pathological cardiac remodeling induced by aggravated afterload largely by activating the Kif15/TGF-β1 axis. This result further complements the mechanisms of communication among different cells in the heart, providing novel therapeutic targets for heart failure.

POS0966 DEVELOPMENT AND VALIDATION OF AN ANKYLOSING SPONDYLITIS RISK PREDICTION MODEL USING LONGITUDINAL REAL-WORLD DATA FROM A LARGE INTEGRATED HEALTHCARE DELIVERY SYSTEM

Background

Early detection and diagnosis of Ankylosing spondylitis (AS) is challenging due to heterogeneity in disease presentation, lack of specific biomarkers and high prevalence of mechanical back-pain that is difficult to distinguish from inflammatory back-pain. However, if diagnosed and treated early, the risk of AS complications and disease progression can be slowed.

Objectives

To develop and validate a risk prediction model for early identification of patients at high risk of AS, using a large longitudinal real-world clinical data in the US.

Methods

This retrospective study included all members aged ≥ 21 years with back pain symptoms who were enrolled in the Kaiser Permanente Southern California health plan between 01/2009-12/2013. Patients who presented with back pain symptoms at a physician visit were followed until 12/2020 to see if they subsequently developed AS. The cohort was randomly divided into a training (60%) and a validation (40%) sample. A proportional odds model was specified to create a risk score for AS in the training sample. Best fit model was determined based on Area Under the Curve (AUC) and Akaike Information Criterion (AIC). The cut off threshold of “high-risk” was based on Youden’s (1950) index.1 We assessed the model performance for internal validity using split-samples. The model was further validated using manual chart review of 900 patient records. These 900 records were selected such that 70% (N=630) met the high-risk cut-off and the remainder had scores below the cut-off. We also derived the probability of AS in each chart reviewed case using the method proposed by Feldtkeller et al. (2013) and Rudwaleit et al. (2006).2,3

Results

The cohort comprised 527,509 members with mean age 54 years and majority female (58%). Sixty-six percent were White race and 33% were Hispanic ethnicity. The crude incidence of AS was 1% and increased steadily during the follow-up period (Figure 1). The final risk prediction model included 15 risk factors and had an AUC of 0.72 (Table 1). Using Youden’s index, a cut-off value of 11 or higher was identified as the threshold to define high-risk. No evidence of overfitting to our training sample was observed based on the split-sample analysis. The model validation based on manual chart review of 900 records showed sufficient ability to discriminate between those at high-risk vs those not identified to be high-risk. When a concrete rule out or rule in determination could be made using Feldtkeller et al. approach, our model correctly classified 75% of such records.

Table 1.

Final Model Coefficients and Derived Risk Score

Model CoefficientPr(>|z|)Risk ScoreAge above 45 years0.1460.0111.46Male Sex-0.292<0.001-2.92White Race0.259<0.0012.59Non-Hispanic Ethnicity0.177<0.0011.77Corticosteroid Use (Yes/No)0.235<0.0012.35*NSAID User (Yes/No)0.202<0.0012.02Opioid Analgesic User (Yes/No)0.416<0.0014.16Had Enthesitis (Yes/No)0.298<0.0012.98Had Disorders of the Back (Yes/No)0.973<0.0019.73Had Fatigue and/or Malaise (Yes/No)0.1550.0561.55Had Psoriasis (Yes/No)0.2880.0082.88Had Spondylosis (Yes/No)0.838<0.0018.38Had Synovitis (Yes/No)0.1430.0661.43Had Uveitis (Yes/No)0.6210.0076.21Depression Diagnosis (Yes/No)0.0990.0170.99

* NSAID: Non-steroidal anti-inflammatory drugs

Figure 1.

Cumulative Incidence Over Time (in Days)

Conclusion

To aid early detection, we have developed and validated an AS risk prediction model with an easy to implement scoring system using demographics, medication use and diagnosis data that is routinely collected in clinical practice.

References:

[1]Youden WJ. Index for rating diagnostic tests. Cancer. 1950;3(1):32-35.

[2]Feldtkeller E, Rudwaleit M, Zeidler H. Easy probability estimation of the diagnosis of early axial spondyloarthritis by summing up scores. Rheumatology (Oxford, England). 2013;52(9):1648-1650

[3]Rudwaleit M, Feldtkeller E, Sieper J. Easy assessment of axial spondyloarthritis (early ankylosing spondylitis) at the bedside. Ann Rheum Dis 2006;65:1251-2.

Disclosure of Interests

Aniket Kawatkar Grant/research support from: Novartis, Medac, Esther Yi Employee of: Novartis, Erika Estrada Grant/research support from: Novartis, Jose Pio Grant/research support from: Novartis, Cecilia Portugal Grant/research support from: Novartis, David Yi Grant/research support from: Novartis, Talar Habeshian Grant/research support from: Novartis, David Wei Employee of: Novartis, Steven Lee Grant/research support from: Novartis

[Efficacy of high-voltage long-duration pulsed radiofrequency treatment in patients with neuralgia resulting from failed back surgery syndrome]

Objective: To explore the efficacy and safety of high-voltage long-duration pulsed radiofrequency (PRF) treatment in patients with neuralgia resulting from failed back surgery syndrome (FBSS). Methods: The clinical data of 58 patients diagnosed with neuralgia resulting from FBSS in the Department of Pain Medicine, Peking University Third Hospital from January 2017 to January 2020 were retrospectively analyzed. The patients were divided into two groups according to the treatment method. Experimental group (n=28) underwent high-voltage long-duration PRF therapy, using ultrasound and X-ray guidance to target the spinal nerve of the affected side, while control group (n=30) was applied with the standard pulsed radiofrequency therapy. Visual analogue scale (VAS), Oswestry disability index (ODI), 36-item short form health survey (SF-36), patient health questionnaire (PHQ-9) before treatment and at 1 week, 1 month, and 6 months after treatment were recorded. Meanwhile, postprocedural complications and adverse reactions were also collected. Results: VAS, ODI, SF-36 and PHQ-9 scores at 1 week, 1 month, and 6 months after treatment were significantly improved in both groups compared with their respective pre-treatment baseline scores (all P<0.01). The differences of VAS, ODI, and PHQ-9 scores between the two groups were not statistically significant at 1 month after treatment (all P>0.05). However, VAS, ODI, and PHQ-9 scores were lower in experiment group than those in control group at 6 months after treatment (all P<0.05). The marked improvement rate and total effective rate at 6 months after treatment in experiment group was 78.6% (22/28) and 92.9% (26/28), respectively, which were higher than that of control group [60.0% (18/30) and 83.3% (25/30), respectively], but the differences were not statistically significant (both P>0.05). No serious complications occurred during the whole period of treatment. Conclusions: Both treatments can effectively relieve the lower limb neuralgia. High-voltage long-term PRF has better efficacy and longer duration than standard PRF.

A setup to measure the temperature-dependent heating power of magnetically heated nanoparticles up to high temperature

Magnetic heating, namely, the use of heat released by magnetic nanoparticles (MNPs) excited with a high-frequency magnetic field, has so far been mainly used for biological applications. More recently, it has been shown that this heat can be used to catalyze chemical reactions, some of them occurring at temperatures up to 700 °C. The full exploitation of MNP heating properties requires the knowledge of the temperature dependence of their heating power up to high temperatures. Here, a setup to perform such measurements is described based on the use of a pyrometer for high-temperature measurements and on a protocol based on the acquisition of cooling curves, which allows us to take into account calorimeter losses. We demonstrate that the setup permits to perform measurements under a controlled atmosphere on solid state samples up to 550 °C. It should in principle be able to perform measurements up to 900 °C. The method, uncertainties, and possible artifacts are described and analyzed in detail. The influence on losses of putting under vacuum different parts of the calorimeter is measured. To illustrate the setup possibilities, the temperature dependence of heating power is measured on four samples displaying very different behaviors. Their heating power increases or decreases with temperature, displaying temperature sensibilities ranging from -2.5 to +4.4% K^-1. This setup is useful to characterize the MNPs for magnetically heated catalysis applications and to produce data that will be used to test models permitting to predict the temperature dependence of MNP heating power.

Sex Differences of Clinical Presentation and Outcomes in Propensity-Matched Patients with Acute Type A Aortic Dissection

OBJECTIVES

To assess sex differences of clinical presentation and outcomes in propensity-matched patients with acute type A aortic dissection (AAAD).

METHODS

We collected the clinical data of patients with AAAD from a single heart center between January 2009 and July 2014. After propensity score matching, we compared differences in clinical presentation and outcomes of patients with AAAD between men and women.

RESULTS

There were 590 patients (295 men and 295 women) with AAAD through propensity matching on demographics and patients' history. We found that the presentation and diagnosis of AAAD often were more delayed in women. Severe signs of congestive heart failure (9.8% vs. 5.1%, P = 0.017), cardiac tamponade/shock (9.1% vs. 4.1%, P < 0.001), and periaortic hematoma (26.4% vs. 21.7%, P < 0.001) were more commonly presented in women. Surgery was more commonly performed in men than in women (95.4% (281/295) vs. 91.5% (270/295), P = 0.045), indicating the association of sex with surgical decision. To investigate the association of sex with outcomes after surgery, patients who underwent surgical treatment were re-matched (262 men and 262 women) by propensity score. Women suffered from greater in-hospital mortality than men (8.4% vs. 3.4%, P < 0.001). Postoperative complications of congestive heart failure (9.1% vs. 3.8%, P < 0.001), visceral ischemia (6.8% vs. 1.1%, P < 0.001), and limb ischemia (7.6% vs. 1.5%, P < 0.001) were more frequent in women. For women, prolonged operative time may increase in-hospital mortality, especially after 12 hours from the start of surgery (30.0% vs. 14.3%, P < 0.001). Kaplan-Meier survival analysis indicated worse late outcomes in women in the matched surgery group (log-rank P = 0.012).

CONCLUSIONS

Our analysis provides new insights into sex differences in clinical presentation and outcomes of AAAD.

Melatonin protects against thoracic aortic aneurysm and dissection through SIRT1-dependent regulation of oxidative stress and vascular smooth muscle cell loss

Melatonin functions as an endogenous protective molecule in multiple vascular diseases, whereas its effects on thoracic aortic aneurysm and dissection (TAAD) and underlying mechanisms have not been reported. In this study, TAAD mouse model was successfully induced by β-aminopropionitrile fumarate (BAPN). We found that melatonin treatment remarkably prevented the deterioration of TAAD, evidenced by decreased incidence, ameliorated aneurysmal dilation and vascular stiffness, improved aortic morphology, and inhibited elastin degradation, macrophage infiltration, and matrix metalloproteinase expression. Moreover, melatonin blunted oxidative stress damage and vascular smooth muscle cell (VSMC) loss. Notably, BAPN induced a decrease in SIRT1 expression and activity of mouse aorta, whereas melatonin treatment reversed it. Further mechanistic study demonstrated that blocking SIRT1 signaling partially inhibited these beneficial effects of melatonin on TAAD. Additionally, the melatonin receptor was involved in this phenomenon. Our study is the first to report that melatonin exerts therapeutic effects against TAAD by reducing oxidative stress and VSMC loss via activation of SIRT1 signaling in a receptor-dependent manner, thus suggesting a novel therapeutic strategy for TAAD.

[Analysis of anxiety, depression and related factors in patients with chronic lumbocrural pain before minimally invasive surgery]

OBJECTIVE

To investigate anxiety and/or depression status of patients with chronic lumbocrural pain, and to further analyze related risk factors of anxiety and/or depression .

METHODS

Retrospective analysis of the medical data of patients who suffered from chronic lumbocrural pain caused by lumbar disc herniation and/or lumbar spinal stenosis and received minimally invasive surgery from March 2018 to April 2018. General data (including age, gender, education levels, past history, sleep order and medical insurance), numeric rating scale(NRS), Japanese Orthopedic Association(JOA) back pain scale and hospital anxiety and depression scale(HADS) were collected for analysis. The basic demographic data and clinic data were analyzed, possible related risk factors associated were analyzed by univariate analysis, and multivariate Logistic regression analysis was further used to find the relative independent risk factors and included all the predictive variables with P values less than 0.05 as covariates.

RESULTS

A total of 91 patients met the inclusion criteria and finished this study, the mean HADS score for anxiety was 8.1±4.2, 48(52.7%) respondents were screened positive for anxiety, while the rest 43(47.3%) patients had negative anxiety state, the mean HDDS score for depression was 6.9±4.9, 38(41.8%) respondents were screened positive for depression, and the rest 53(58.2%) patients were not depressed, and 56(61.5%) patients experienced anxiety or depression. There were significant difference in sleep disorder, JOA score and leg NRS score between the patients with and without anxiety(P<0.05), and the significant differences were also found in age, sleep disorder and JOA score between the patients with and without depression(P<0.05), Logistic regression analysis further showed that the JOA score and sleep disorder were risk factors for anxiety, and the JOA score was risk factor for depression.

CONCLUSION

Patients with chronic lumbocrural pain are often accompanied by anxiety and/or depression before minimally surgery, the low JOA score and sleep disturbance increased the risk of presenting anxiety, and the low JOA score increased the risk of developing depression. It is necessary to evaluate mental status and related risk factors before surgery.

Modified Glucose-Insulin-Potassium Regimen Provides Cardioprotection With Improved Tissue Perfusion in Patients Undergoing Cardiopulmonary Bypass Surgery

Background Laboratory studies demonstrate glucose-insulin-potassium (GIK) as a potent cardioprotective intervention, but clinical trials have yielded mixed results, likely because of varying formulas and timing of GIK treatment and different clinical settings. This study sought to evaluate the effects of modified GIK regimen given perioperatively with an insulin-glucose ratio of 1:3 in patients undergoing cardiopulmonary bypass surgery. Methods and Results In this prospective, randomized, double-blinded trial with 930 patients referred for cardiac surgery with cardiopulmonary bypass, GIK (200 g/L glucose, 66.7 U/L insulin, and 80 mmol/L KCl) or placebo treatment was administered intravenously at 1 mL/kg per hour 10 minutes before anesthesia and continuously for 12.5 hours. The primary outcome was the incidence of in-hospital major adverse cardiac events including all-cause death, low cardiac output syndrome, acute myocardial infarction, cardiac arrest with successful resuscitation, congestive heart failure, and arrhythmia. GIK therapy reduced the incidence of major adverse cardiac events and enhanced cardiac function recovery without increasing perioperative blood glucose compared with the control group. Mechanistically, this treatment resulted in increased glucose uptake and less lactate excretion calculated by the differences between arterial and coronary sinus, and increased phosphorylation of insulin receptor substrate-1 and protein kinase B in the hearts of GIK-treated patients. Systemic blood lactate was also reduced in GIK-treated patients during cardiopulmonary bypass surgery. Conclusions A modified GIK regimen administered perioperatively reduces the incidence of in-hospital major adverse cardiac events in patients undergoing cardiopulmonary bypass surgery. These benefits are likely a result of enhanced systemic tissue perfusion and improved myocardial metabolism via activation of insulin signaling by GIK. Clinical Trial Registration URL: clinicaltrials.gov. Identifier: NCT01516138.

De novo transcriptome characterisation of two auxin-related genes associated with plant growth habit in Astragalus adsurgens Pall

Astragalus adsurgens Pall., a perennial legume native to China, is commonly used as a forage crop. And it has great value for sustainable development of grasslands in arid and semi arid regions. However, to date, little is known regarding the A. adsurgens genome, and no studies have determined whether it would be possible to improve the germplasm of A. adsurgens through genetic modification. In this study, we used an RNA-seq protocol to generate a de novo transcriptome including 151,516 unigenes of A. adsurgens. We compared the transcriptomes of A. adsurgens having different growth habits (prostrate/erect) and identified 14,133 single nucleotide polymorphism sites (SNP) in 8,139 unigenes. Differential expression gene (DEG) analysis suggested that 10,982 unigenes were up-regulated in the prostrate plant relative to the erect plant, while 10,607 unigenes were down-regulated. Of the 21,589 DEG, Unigene72782_All (LAX4) and CL12494.Contig3_All (TIR1), an auxin transporter gene and an auxin transport inhibitor gene, respectively, were predicted to influence the growth habit of A. adsurgens, which were verified by qRT-PCR in these phenotypes. These results suggest that auxin transport was more active in the prostrate plant than in the erect plant, resulting in asymmetric distribution of auxin that affects the growth habit of A. adsurgens. Overall, this study may provide a basis for future research on key genes in A. adsurgens and may deepen our understanding of the molecular mechanisms regulating plant growth habit.

Genomic and epidemiological monitoring of yellow fever virus transmission potential

The yellow fever virus (YFV) epidemic in Brazil is the largest in decades. The recent discovery of YFV in Brazilian Aedes species mosquitos highlights a need to monitor the risk of reestablishment of urban YFV transmission in the Americas. We use a suite of epidemiological, spatial, and genomic approaches to characterize YFV transmission. We show that the age and sex distribution of human cases is characteristic of sylvatic transmission. Analysis of YFV cases combined with genomes generated locally reveals an early phase of sylvatic YFV transmission and spatial expansion toward previously YFV-free areas, followed by a rise in viral spillover to humans in late 2016. Our results establish a framework for monitoring YFV transmission in real time that will contribute to a global strategy to eliminate future YFV epidemics.

Melatonin protects against the pathological cardiac hypertrophy induced by transverse aortic constriction through activating PGC-1β: In vivo and in vitro studies

Melatonin, a circadian molecule secreted by the pineal gland, confers a protective role against cardiac hypertrophy induced by hyperthyroidism, chronic hypoxia, and isoproterenol. However, its role against pressure overload-induced cardiac hypertrophy and the underlying mechanisms remains elusive. In this study, we investigated the pharmacological effects of melatonin on pathological cardiac hypertrophy induced by transverse aortic constriction (TAC). Male C57BL/6 mice underwent TAC or sham surgery at day 0 and were then treated with melatonin (20 mg/kg/day, via drinking water) for 4 or 8 weeks. The 8-week survival rate following TAC surgery was significantly increased by melatonin. Melatonin treatment for 8 weeks markedly ameliorated cardiac hypertrophy. Compared with the TAC group, melatonin treatment for both 4 and 8 weeks reduced pulmonary congestion, upregulated the expression level of α-myosin heavy chain, downregulated the expression level of β-myosin heavy chain and atrial natriuretic peptide, and attenuated the degree of cardiac fibrosis. In addition, melatonin treatment slowed the deterioration of cardiac contractile function caused by pressure overload. These effects of melatonin were accompanied by a significant upregulation in the expression of peroxisome proliferator-activated receptor-gamma co-activator-1 beta (PGC-1β) and the inhibition of oxidative stress. In vitro studies showed that melatonin also protects against angiotensin II-induced cardiomyocyte hypertrophy and oxidative stress, which were largely abolished by knocking down the expression of PGC-1β using small interfering RNA. In summary, our results demonstrate that melatonin protects against pathological cardiac hypertrophy induced by pressure overload through activating PGC-1β.

Ambipolar transport and magneto-resistance crossover in a Mott insulator, Sr2IrO4

Electric field effect (EFE) controlled magnetoelectric transport in thin films of undoped and La-doped Sr₂IrO₄ (SIO) is investigated using ionic liquid gating. The temperature dependent resistance measurements exhibit insulating behavior in chemically and EFE doped samples with the band filling up to 10%. The ambipolar transport across the Mott gap is demonstrated by EFE tuning of the channel resistance and chemical doping. We observe a crossover from high temperature negative to low temperature positive magnetoresistance around  ∼80-90 K, irrespective of the filling. This temperature and magnetic field dependent crossover is discussed in the light of conduction mechanisms of SIO, especially variable range hopping (VRH), and its relevance to the insulating ground state of SIO.

Membrane receptor-dependent Notch1/Hes1 activation by melatonin protects against myocardial ischemia-reperfusion injury: in vivo and in vitro studies

Melatonin confers profound protective effect against myocardial ischemia-reperfusion injury (MI/RI). Activation of Notch1/Hairy and enhancer of split 1 (Hes1) signaling also ameliorates MI/RI. We hypothesize that melatonin attenuates MI/RI-induced oxidative damage by activating Notch1/Hes1 signaling pathway with phosphatase and tensin homolog deleted on chromosome 10 (Pten)/Akt acting as the downstream signaling pathway in a melatonin membrane receptor-dependent manner. Male Sprague Dawley rats were treated with melatonin (10 mg/kg/day) for 4 wk and then subjected to MI/R surgery. Melatonin significantly improved cardiac function and decreased myocardial apoptosis and oxidative damage. Furthermore, in cultured H9C2 cardiomyocytes, melatonin (100 μmol/L) attenuated simulated ischemia-reperfusion (SIR)-induced myocardial apoptosis and oxidative damage. Both in vivo and in vitro study demonstrated that melatonin treatment increased Notch1, Notch1 intracellular domain (NICD), Hes1, Bcl-2 expressions, and p-Akt/Akt ratio and decreased Pten, Bax, and caspase-3 expressions. However, these protective effects conferred by melatonin were blocked by DAPT (the specific inhibitor of Notch1 signaling), luzindole (the antagonist of melatonin membrane receptors), Notch1 siRNA, or Hes1 siRNA administration. In summary, our study demonstrates that melatonin treatment protects against MI/RI by modulating Notch1/Hes1 signaling in a receptor-dependent manner and Pten/Akt signaling pathways are key downstream mediators.

Reduced silent information regulator 1 signaling exacerbates myocardial ischemia-reperfusion injury in type 2 diabetic rats and the protective effect of melatonin

Diabetes mellitus (DM) increases myocardial oxidative stress and endoplasmic reticulum (ER) stress. Melatonin confers cardioprotective effect by suppressing oxidative damage. However, the effect and mechanism of melatonin on myocardial ischemia-reperfusion (MI/R) injury in type 2 diabetic state are still unknown. In this study, we developed high-fat diet-fed streptozotocin (HFD-STZ) rat, a well-known type 2 diabetic model, to evaluate the effect of melatonin on MI/R injury with a focus on silent information regulator 1 (SIRT1) signaling, oxidative stress, and PERK/eIF2α/ATF4-mediated ER stress. HFD-STZ treated rats were exposed to melatonin treatment in the presence or the absence of sirtinol (a SIRT1 inhibitor) and subjected to MI/R surgery. Compared with nondiabetic animals, type 2 diabetic rats exhibited significantly decreased myocardial SIRT1 signaling, increased apoptosis, enhanced oxidative stress, and ER stress. Additionally, further reduced SIRT1 signaling, aggravated oxidative damage, and ER stress were found in diabetic animals subjected to MI/R surgery. Melatonin markedly reduced MI/R injury by improving cardiac functional recovery and decreasing myocardial apoptosis in type 2 diabetic animals. Melatonin treatment up-regulated SIRT1 expression, reduced oxidative damage, and suppressed PERK/eIF2α/ATF4 signaling. However, these effects were all attenuated by SIRT1 inhibition. Melatonin also protected high glucose/high fat cultured H9C2 cardiomyocytes against simulated ischemia-reperfusion injury-induced ER stress by activating SIRT1 signaling while SIRT1 siRNA blunted this action. Taken together, our study demonstrates that reduced cardiac SIRT1 signaling in type 2 diabetic state aggravates MI/R injury. Melatonin ameliorates reperfusion-induced oxidative stress and ER stress via activation of SIRT1 signaling, thus reducing MI/R damage and improving cardiac function.

Endoplasmic reticulum stress mediates the anti-inflammatory effect of ethyl pyruvate in endothelial cells

Ethyl pyruvate (EP) is a simple aliphatic ester of the metabolic intermediate pyruvate that has been demonstrated to be a potent anti-inflammatory agent in a variety of in vivo and in vitro model systems. However, the protective effects and mechanisms underlying the actions of EP against endothelial cell (EC) inflammatory injury are not fully understood. Previous studies have confirmed that endoplasmic reticulum stress (ERS) plays an important role in regulating the pathological process of EC inflammation. In this study, our aim was to explore the effects of EP on tumor necrosis factor-α (TNF-α)-induced inflammatory injury in human umbilical vein endothelial cells (HUVECs) and to explore the role of ERS in this process. TNF-α treatment not only significantly increased the adhesion of monocytes to HUVECs and inflammatory cytokine (sICAM1, sE-selectin, MCP-1 and IL-8) production in cell culture supernatants but it also increased ICAM and MMP9 protein expression in HUVECs. TNF-α also effectively increased the ERS-related molecules in HUVECs (GRP78, ATF4, caspase12 and p-PERK). EP treatment effectively reversed the effects of the TNF-α-induced adhesion of monocytes on HUVECs, inflammatory cytokines and ERS-related molecules. Furthermore, thapsigargin (THA, an ERS inducer) attenuated the protective effects of EP against TNF-α-induced inflammatory injury and ERS. The PERK siRNA treatment not only inhibited ERS-related molecules but also mimicked the protective effects of EP to decrease TNF-α-induced inflammatory injury. In summary, we have demonstrated for the first time that EP can effectively reduce vascular endothelial inflammation and that this effect at least in part depends on the attenuation of ERS.

A review of melatonin as a suitable antioxidant against myocardial ischemia-reperfusion injury and clinical heart diseases

Cardiac tissue loss is one of the most important factors leading to the unsatisfactory recovery even after treatment of ischemic heart disease. Melatonin, a circadian molecule with marked antioxidant properties, protects against ischemia-reperfusion (IR) injury. In particular, the myocardial protection of melatonin is substantial. We initially focus on the cardioprotective effects of melatonin in myocardial IR. These studies showed how melatonin preserves the microstructure of the cardiomyocyte and reduces myocardial IR injury. Thereafter, downstream signaling pathways of melatonin were summarized including Janus kinase 2/signal transducers and activators of transcription 3, nitric oxide-synthase, and nuclear factor erythroid 2 related factor 2. Herein, we propose the clinical applications of melatonin in several ischemic heart diseases. Collectively, the information summarized in this review (based on in vitro, animal, and human studies) should serve as a comprehensive reference for the action of melatonin in cardioprotection and hopefully will contribute to the design of future experimental research.

Anisotropic magnetoresistance in an antiferromagnetic semiconductor

Recent studies in devices comprising metal antiferromagnets have demonstrated the feasibility of a novel spintronic concept in which spin-dependent phenomena are governed by an antiferromagnet instead of a ferromagnet. Here we report experimental observation of the anisotropic magnetoresistance in an antiferromagnetic semiconductor Sr2IrO4. Based on ab initio calculations, we associate the origin of the phenomenon with large anisotropies in the relativistic electronic structure. The antiferromagnet film is exchange coupled to a ferromagnet, which allows us to reorient the antiferromagnet spin-axis in applied magnetic fields via the exchange spring effect. We demonstrate that the semiconducting nature of our AFM electrode allows us to perform anisotropic magnetoresistance measurements in the current-perpendicular-to-plane geometry without introducing a tunnel barrier into the stack. Temperature-dependent measurements of the resistance and anisotropic magnetoresistance highlight the large, entangled tunabilities of the ordinary charge and spin-dependent transport in a spintronic device utilizing the antiferromagnet semiconductor.

Clinical features of acute aortic dissection from the Registry of Aortic Dissection in China

OBJECTIVE

To establish a systematic registry of aortic dissection in China, assess the clinical features of Chinese patients with acute aortic dissection (AAD), and compare our results with the data published by the International Registry of Acute Aortic Dissection (IRAD).

METHODS

We established the first Registry of Aortic Dissection in China (Sino-RAD) in 2011. Then we evaluated 1003 patients with AAD in Sino-RAD and compared our results with those reported by IRAD.

RESULTS

Compared with IRAD, the patients with AAD in Sino-RAD were significantly younger. Also, the ratio of male patients in Sino-RAD was significantly greater for the total cohort and the type A and B cohorts. The overall in-hospital mortality was 10.3% in Sino-RAD. For type A dissection, more patients in Sino-RAD received medical treatment and fewer received surgical treatment. The overall mortality, mortality of medical treatment, and mortality of surgical treatment was lower in Sino-RAD. In type B dissection, fewer patients in Sino-RAD received medical and surgical treatment and more received endovascular treatment.

CONCLUSIONS

The first Sino-RAD, including 15 large cardiovascular centers throughout China, was established. Our data were compared with those reported by IRAD. We found that, compared with Western populations, Chinese patients with AAD showed 6 differences, including earlier onset, more male patients, a low incidence of hypertension, a low incidence of chest pain, a high incidence of back pain, great differences in the choice of therapeutic strategies, and relatively low in-hospital mortality.

Induced magnetization in La0.7Sr0.3MnO3/BiFeO3 superlattices

Using polarized neutron reflectometry, we observe an induced magnetization of 75 ± 25 kA/m at 10 K in a La(0.7)Sr(0.3)MnO(3) (LSMO)/BiFeO(3) superlattice extending from the interface through several atomic layers of the BiFeO(3) (BFO). The induced magnetization in BFO is explained by density functional theory, where the size of band gap of BFO plays an important role. Considering a classical exchange field between the LSMO and BFO layers, we further show that magnetization is expected to extend throughout the BFO, which provides a theoretical explanation for the results of the neutron scattering experiment.

Room-temperature antiferromagnetic memory resistor

The bistability of ordered spin states in ferromagnets provides the basis for magnetic memory functionality. The latest generation of magnetic random access memories rely on an efficient approach in which magnetic fields are replaced by electrical means for writing and reading the information in ferromagnets. This concept may eventually reduce the sensitivity of ferromagnets to magnetic field perturbations to being a weakness for data retention and the ferromagnetic stray fields to an obstacle for high-density memory integration. Here we report a room-temperature bistable antiferromagnetic (AFM) memory that produces negligible stray fields and is insensitive to strong magnetic fields. We use a resistor made of a FeRh AFM, which orders ferromagnetically roughly 100 K above room temperature, and therefore allows us to set different collective directions for the Fe moments by applied magnetic field. On cooling to room temperature, AFM order sets in with the direction of the AFM moments predetermined by the field and moment direction in the high-temperature ferromagnetic state. For electrical reading, we use an AFM analogue of the anisotropic magnetoresistance. Our microscopic theory modelling confirms that this archetypical spintronic effect, discovered more than 150 years ago in ferromagnets, is also present in AFMs. Our work demonstrates the feasibility of fabricating room-temperature spintronic memories with AFMs, which in turn expands the base of available magnetic materials for devices with properties that cannot be achieved with ferromagnets.

Transcatheter versus surgical closure of perimembranous ventricular septal defects in children: a randomized controlled trial

OBJECTIVES

The objective of this study was to evaluate the safety and efficacy of the surgical versus transcatheter approach to correct perimembranous ventricular septal defects (pmVSDs) in a prospective, randomized, controlled clinical trial.

BACKGROUND

pmVSD is a common congenital heart disease in children. Surgical closure of pmVSD is a well-established therapy but requires open-heart surgery with cardiopulmonary bypass. Although the transcatheter approach is associated with significant incidence of complete atrioventricular block, it may provide a less invasive alternative. Critical comparison of the safety and efficacy of the 2 interventions necessitates a prospective, randomized, controlled trial.

METHODS

Between January 2009 and July 2010, 229 children with pmVSD were randomly assigned to surgical or transcatheter intervention. Clinical, laboratory, procedural, and follow-up data over a 2-year period were compared.

RESULTS

Neither group had mortality or major complications. However, statistical analysis of the 2 groups demonstrated significant differences (p < 0.001) in minor adverse events (32 vs. 7), quantity of blood transfused, duration of the procedure, median hospital stay, median intensive care unit stay, median hospitalization cost, and median blood loss. During a median follow-up of 2 years, the left ventricular end-diastolic dimension of both groups returned to normal and there was no difference in closure rate, adverse events, and complications between groups.

CONCLUSIONS

Transcatheter device closure and surgical repair are effective interventions with excellent midterm results for treating pmVSD in children. Transcatheter device closure has a lower incidence of myocardial injury, less blood transfused, faster recovery, shorter hospital stay, and lower medical expenses. (Transcatheter Closure Versus Surgery of Perimembranous Ventricular Septal Defects; NCT00890799).

SIRT1 activation by curcumin pretreatment attenuates mitochondrial oxidative damage induced by myocardial ischemia reperfusion injury

Ischemia reperfusion (IR) injury (IRI) is harmful to the cardiovascular system and causes mitochondrial oxidative stress. Silent information regulator 1 (SIRT1), a type of histone deacetylase, contributes to IRI. Curcumin (Cur) is a strong natural antioxidant and is the active component in Curcuma longa; Cur has protective effects against IRI and may regulate the activity of SIRT1. This study was designed to investigate the protective effect of Cur pretreatment on myocardial IRI and to elucidate this potential mechanism. Isolated and in vivo rat hearts and cultured neonatal rat cardiomyocytes were subjected to IR. Prior to this procedure, the hearts or cardiomyocytes were exposed to Cur in the absence or presence of the SIRT1 inhibitor sirtinol or SIRT1 siRNA. Cur conferred a cardioprotective effect, as shown by improved postischemic cardiac function, decreased myocardial infarct size, decreased myocardial apoptotic index, and several biochemical parameters, including the up-regulation of the antiapoptotic protein Bcl2 and the down-regulation of the proapoptotic protein Bax. Sirtinol and SIRT1 siRNA each blocked the Cur-mediated cardioprotection by inhibiting SIRT1 signaling. Cur also resulted in a well-preserved mitochondrial redox potential, significantly elevated mitochondrial superoxide dismutase activity, and decreased formation of mitochondrial hydrogen peroxide and malondialdehyde. These observations indicated that the IR-induced mitochondrial oxidative damage was remarkably attenuated. However, this Cur-elevated mitochondrial function was reversed by sirtinol or SIRT1 siRNA treatment. In summary, our results demonstrate that Cur pretreatment attenuates IRI by reducing IR-induced mitochondrial oxidative damage through the activation of SIRT1 signaling.

C1q/tumor necrosis factor-related protein-9, a novel adipocyte-derived cytokine, attenuates adverse remodeling in the ischemic mouse heart via protein kinase A activation

BACKGROUND

C1q/tumor necrosis factor-related protein-9 (CTRP9) is a newly identified adiponectin paralog with established metabolic regulatory properties. However, the role of CTRP9 in postmyocardial infarction remodeling remains completely unknown. This study determined whether CTRP9 may regulate cardiac remodeling after acute myocardial infarction (AMI) and elucidated the underlying mechanisms.

METHODS AND RESULTS

Male adult mice were subject to AMI by left anterior descending coronary artery ligation or sham surgery and treated with saline (vehicle) or globular CTRP9 via peritoneal implant osmotic pumps for 6 weeks. H9C2 cardiac cell lines were used in vitro for determining underlying mechanisms. Adipocyte CTRP9 expression and plasma CTRP9 levels were both significantly reduced after AMI. Compared with vehicle, CTRP9 treatment improved animal survival rate (P<0.05), restored cardiac function (P<0.05), attenuated adverse remodeling (P<0.01), and ameliorated cardiomyocyte apoptosis and fibrosis after AMI (P<0.01). Among the multiple antiremodeling molecules determined, AMP-activated protein kinase, protein kinase A (PKA), and Akt were significantly activated in CTRP9-treated heart. Surprisingly, CTRP9 remains cardioprotective in mice with cardiomyocyte-specific overexpression of a mutant AMP-activated protein kinase α2 subunit (AMPK-DN). Additional in vitro experiments demonstrated that administration of either PKA inhibitor or PKA-specific small interfering RNA virtually abolished the antiapoptotic effect of CTRP9 (P<0.05), whereas inhibition of Akt is less effective in blocking CTRP9 cardioprotection. Finally, CTRP9 phosphorylates BCL-2-associated agonist of cell death at its multiple antiapoptotic sites, an effect blocked by PKA inhibitor.

CONCLUSIONS

We demonstrate that adipokine CTRP9 attenuates adverse cardiac remodeling after AMI, largely via a PKA-dependent pathway.

Induction of angiogenesis by controlled delivery of vascular endothelial growth factor using nanoparticles

AIMS

The study reports the feasibility and efficiency of vascular endothelial growth factor (VEGF) delivery using nanoparticles synthesized from glycidyl methacrylated dextran (Dex-GMA) and gelatin for therapeutic angiogenesis.

METHODS

The nanoparticles were prepared using phase separation method, and the drug release profile was determined by ELISA study. The bioactivity of VEGF-incorporated nanoparticles (VEGF-NPs) were determined using tube formation assay. A rabbit hind limb ischemia model was employed to evaluate the in vivo therapeutic effect. Blood perfusion was measured by single-photon emission computed tomography (SPECT). Vessel formation was evaluated by contrast angiography and immunohistochemistry.

RESULTS

The nanoparticles synthesized were spherical in shape with evenly distributed size of about 130 ± 3.5 nm. The VEGF encapsulated was released in a biphase manner, with the majority of 69% released over 1-12 days. Tube formation assays showed increased tubular structures by VEGF-NP compared with empty nanoparticles and no treatment. Both free VEGF and VEGF-NP significantly increased blood perfusion compared with empty nanoparticles (both P < 0.001), but it was much higher in VEGF-NP-treated limbs (P < 0.001). Contrast angiography and immunohistological analysis also revealed more significant collateral artery formation and higher capillary density in VEGF-NP-treated limbs.

CONCLUSIONS

Dex-GMA and gelatin-based nanoparticles could provide sustained release of VEGF and may serve as a new way for angiogenesis.

JAK2/STAT3 activation by melatonin attenuates the mitochondrial oxidative damage induced by myocardial ischemia/reperfusion injury

Ischemia/reperfusion injury (IRI) is harmful to the cardiovascular system and causes mitochondrial oxidative stress. Numerous data indicate that the JAK2/STAT3 signaling pathway is specifically involved in preventing myocardial IRI. Melatonin has potent activity against IRI and may regulate JAK2/STAT3 signaling. This study investigated the protective effect of melatonin pretreatment on myocardial IRI and elucidated its potential mechanism. Perfused isolated rat hearts and cultured neonatal rat cardiomyocytes were exposed to melatonin in the absence or presence of the JAK2/STAT3 inhibitor AG490 or JAK2 siRNA and then subjected to IR. Melatonin conferred a cardio-protective effect, as shown by improved postischemic cardiac function, decreased infarct size, reduced apoptotic index, diminished lactate dehydrogenase release, up-regulation of the anti-apoptotic protein Bcl2, and down-regulation of the pro-apoptotic protein Bax. AG490 or JAK2 siRNA blocked melatonin-mediated cardio-protection by inhibiting JAK2/STAT3 signaling. Melatonin exposure also resulted in a well-preserved mitochondrial redox potential, significantly elevated mitochondrial superoxide dismutase (SOD) activity, and decreased formation of mitochondrial hydrogen peroxide (H2 O2 ) and malondialdehyde (MDA), which indicates that the IR-induced mitochondrial oxidative damage was significantly attenuated. However, this melatonin-induced effect on mitochondrial function was reversed by AG490 or JAK2 siRNA treatment. In summary, our results demonstrate that melatonin pretreatment can attenuate IRI by reducing IR-induced mitochondrial oxidative damage via the activation of the JAK2/STAT3 signaling pathway.

Abstract 277: Acute Cardiac Insulin Resistance During Cardiopulmonary Bypass in Mini-pigs: Role of Hexosamine Biosynthesis and Protein O-Glycosylation

Our previous study as well as others has demonstrated a strong positive correlation between cardiac insulin signaling and myocardial function in ischemic/reperfused hearts. This study was designed to determine whether cardiac insulin signaling is impaired during cardiopulmonary bypass (CPB) and the possible mechanisms involved. Twelve male mini-pigs were anesthetized and subjected to CPB for 30 min. Blood samples and left ventricle biopsies were taken at pre-bypass (control), aortic cross clamp (AXC) 5 min and AXC release 120 min. Compared with sham-operated group, both blood glucose and insulin levels went up at 120 min after AXC release. Glucose uptake in heart dropped significantly as measured by attenuated coronary arterio-venous glucose difference and reduced cardiac 18 F-fluorodeoxyglucose uptake by Positron Emission Tomography imaging. Furthermore, myocardial insulin signaling was blunted as manifested by decreased phosphorylation of IRS-1, Akt and GSK-3beta (P<0.01, n=4). Interestingly, these changes were associated with a substantial increase of GFAT activity (the rate-limiting enzyme for hexosamine biosynthesis) and a significant increase in protein O-GlcNAcylation in cardiac tissues (P<0.05, n=6). Moreover, pretreatment with Alloxan, an inhibitor of O-GlcNAc-transferase, blocked both the impaired GSK-3beta phosphorylation and the increase in O-GlcNAcylation. Enhancement of cardiac insulin signaling with glucose-insulin-potassium before AXC decreased protein O-GlcNAcylation and ameliorated myocardial dysfunction after CPB. These data indicate the existence of acute myocardial insulin resistance during CPB which is attributable to elevated hexosamine biosynthesis and protein O-glycosylation.

Pterostilbene exerts antitumor activity via the Notch1 signaling pathway in human lung adenocarcinoma cells

Although pterostilbene (PTE) has been shown to have potent antitumor activities against various cancer types, the molecular mechanisms of these activities remain unclear. In this study, we investigated the antitumor activity of PTE against human lung adenocarcinoma in vitro and in vivo and explored the role of the Notch1 signaling pathway in this process. PTE treatment resulted in a dose- and time-dependent decrease in the viability of A549 cells. Additionally, PTE exhibited strong antitumor activity, as evidenced not only by a reduced mitochondrial membrane potential (MMP) and a decreased intracellular glutathione content but also by increases in the apoptotic index and the level of reactive oxygen species (ROS). Furthermore, PTE treatment induced the activation of the Notch1 Intracellular Domain (NICD) protein and activated Hes1. DAPT (a gamma secretase inhibitor) and Notch1 siRNA prevented the induction of NICD and Hes1 activation by PTE treatment and sensitized the cells to PTE treatment. The down-regulation of Notch signaling also prevented the activation of pro-survival pathways (most notably the PI3K/Akt pathway) after PTE treatment. In summary, lung adenocarcinoma cells may enhance Notch1 activation as a protective mechanism in response to PTE treatment. Combining a gamma secretase inhibitor with PTE treatment may represent a novel approach for treating lung adenocarcinoma by inhibiting the survival pathways of cancer cells.

Full electric control of exchange bias

We report the creation of a multiferroic field effect device with a BiFeO(3) (BFO) (antiferromagnetic-ferroelectric) gate dielectric and a La(0.7)Sr(0.3)MnO(3) (LSMO) (ferromagnetic) conducting channel that exhibits direct, bipolar electrical control of exchange bias. We show that exchange bias is reversibly switched between two stable states with opposite exchange bias polarities upon ferroelectric poling of the BFO. No field cooling, temperature cycling, or additional applied magnetic or electric field beyond the initial BFO polarization is needed for this bipolar modulation effect. Based on these results and the current understanding of exchange bias, we propose a model to explain the control of exchange bias. In this model the coupled antiferromagnetic-ferroelectric order in BFO along with the modulation of interfacial exchange interactions due to ionic displacement of Fe(3+) in BFO relative to Mn(3+/4+) in LSMO cause bipolar modulation.

Pigment epithelium-derived factor delays cellular senescence of human mesenchymal stem cells in vitro by reducing oxidative stress

Mesenchymal stem cells (MSCs) are multipotent progenitor cells that represent a promising approach in the field of regenerative medicine; however, this potential diminishes with senescence. Pigment epithelium-derived factor (PEDF) gives some protection by reducing oxidative stress, which is known to accelerate cellular senescence. Thus we hypothesized that PEDF could delay senescence during MSC expansion by reducing oxidative stress. Proliferation and differentiation potentials, oxidative stress, senescence and p53/p16 expressions have been examined. In MSCs cultured under normoxic conditions treated with PEDF, proliferative lifespan in vitro was significantly increased compared with control group not given PEDF, with ∼10 additional population doublings (PD) occurring before terminal growth arrest. Most of the MSCs cultured under normoxic conditions ceased to proliferate after 20-28 PD, while few senescent cells were found in the hypoxic, PEDF-hypoxic and PEDF-normoxic cultures; this was associated with downregulation of p53 and p16 expression and decreased oxidative stress. PEDF also preserved differentiation potentials of MSCs compared with the control group. Thus PEDF suppression of oxidative stress delays cellular senescence and allows greater expansion of MSCs.

Cardioprotective effect of ghrelin in cardiopulmonary bypass involves a reduction in inflammatory response

Background

Ghrelin has been reported to protect the cardiovascular system; however, the cardioprotective effect of ghrelin against cardiopulmonary bypass (CPB) induced myocardial injury are unclear. In this study, the protective effect of ghrelin on CPB induced myocardial injury and the underlying mechanisms were investigated.

Methods and Results

Adult male rats were subjected to CPB and randomly to receive vehicle (n = 8), ghrelin (n = 8), ghrelin plus [D-Lys3]-GHRP-6, a GHSR-1a inhibitor (n = 8), or ghrelin plus wortmannin, a phosphoinositide 3′-kinase (PI3K) inhibitor (n = 8). In vitro study was performed on cultured cardiomyocytes subjected to simulated cardiopulmonary bypass (SCPB). Ghrelin attenuated the inflammatory response, as evidenced by reduced induction of TNF-α, IL-6 and myocardial myeloperoxidase activity and concurrent reduction in apoptosis, oxidative stress, and levels of myocardial injury markers following CPB. Moreover, ghrelin significantly increased cardiac function after CPB. In cultured cardiomyocytes subjected to simulated CPB, ghrelin increased cell viability and decreased the percentage of apoptotic myocytes. Inhibition of ghrelin downstream signaling blocked the cardioprotective effects both in vivo and vitro.

Conclusions

Ghrelin could provide an effective approach to the attenuation of CPB induced myocardial injury. The cardioprotective effects elicited by ghrelin may contribute to the inhibition of inflammatory response through the Akt-activated pathway.

Curcumin attenuates endothelial cell oxidative stress injury through Notch signaling inhibition

Previous studies have demonstrated that Notch signaling pathway plays a regulatory role in cellular oxidative stress injury (OSI). In this study, our aim was to explore the role of the Notch signaling pathway in hydrogen peroxide (H(2)O(2))-induced OSI and the protective effect of curcumin during (H(2)O(2))-induced injury in human umbilical vein endothelial cells (HUVECs). DAPT, a specific inhibitor of the Notch signaling pathway, and Notch1 siRNA were used to study Notch activity. Further, HUVECs were exposed to H(2)O(2) in the absence or presence of curcumin. DAPT and Notch1 siRNA significantly inhibited OSI and the expression of Notch1 and Hes1. Curcumin conferred a protective effect on the HUVECs against H(2)O(2), which was evidenced by improved cell viability, adhesive ability and migratory ability and a decreased apoptotic index, decreased production of reactive oxygen species (ROS) and a reduction in several biochemical parameters. Immunofluorescence and Western blotting analyses demonstrated that H(2)O(2) treatment upregulated the expression of Notch1, Hes1, Caspase3, Bax and cytochrome c downregulated the expression of Bcl2, and treatment with curcumin reversed these effects. We demonstrated for the first time that the inhibition of Notch signaling pathway imparts a protective effect against endothelial OSI. The protective effects of curcumin against OSI are at least in part dependent on Notch1 inhibition.

Acute aortic dissection in China

The clinical profiles and outcomes of acute aortic dissection (AAD) have not been evaluated in China. We retrospectively analyzed, from January 1, 2008 to December 31, 2011, the data from 1,812 patients (mean age 51.1 ± 10.9 years; 77.5% men) with AAD (726 with type A and 1,086 with type B) from 19 large hospitals. Most patients had hypertension and presented with an abrupt onset of chest and/or back pain. Patients with type A AAD were more likely to present with typical symptoms and signs. Computed tomography was the most common initial imaging modality, used in 76.3% of patients with an AAD. The overall in-hospital mortality rate was 17.7%, with most of the deaths occurring within the first week. Surgery was used in 75.3% of patients with type A AAD. The mortality in this cohort was 33.8%. Endovascular treatment was performed in 76.1% of patients with type B AAD. The mortality rate was 2.2%. Multivariate analysis showed that hypertension (odds ratio 2.80, p <0.001), Marfan syndrome (odds ratio 1.76, p = 0.017), anterior chest pain (odds ratio 1.62, p = 0.004), abdominal pain (odds ratio 1.51, p = 0.041), migrating pain (odds ratio 1.56, p = 0.04), and arch vessel involvement (odds ratio 1.70, p <0.001) were predictive factors for increased in-hospital mortality in patients with an AAD. In conclusion, our study has provided insight into the current profiles and outcomes of AAD in China. This knowledge might be useful for clinicians when diagnosing and treating these patients.

Interface control of bulk ferroelectric polarization

The control of material interfaces at the atomic level has led to novel interfacial properties and functionalities. In particular, the study of polar discontinuities at interfaces between complex oxides lies at the frontier of modern condensed matter research. Here we employ a combination of experimental measurements and theoretical calculations to demonstrate the control of a bulk property, namely ferroelectric polarization, of a heteroepitaxial bilayer by precise atomic-scale interface engineering. More specifically, the control is achieved by exploiting the interfacial valence mismatch to influence the electrostatic potential step across the interface, which manifests itself as the biased-voltage in ferroelectric hysteresis loops and determines the ferroelectric state. A broad study of diverse systems comprising different ferroelectrics and conducting perovskite underlayers extends the generality of this phenomenon.