Upregulation of connexin43 by glucose deprivation in H9c2 cells via the extracellular signal‑regulated kinase/mitogen‑activated protein kinase signaling pathway

Cardiac connexin43 (Cx43) serves an essential role in maintaining the functional integrity of the heart. The present study investigated the effect of glucose deprivation (GD) on Cx43 protein expression levels in H9c2 cells, and demonstrated that following 2 h GD, Cx43 protein expression levels in H9c2 cells increased by ~68%. In addition, GD activated the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) signaling pathway, which regulated the expression levels of cardiac Cx43. A MAPK inhibitor and U0126, an ERK inhibitor, abolished the effects of GD on Cx43 expression levels. Under GD, the protein expression levels of Beclin-1, p62 and LC3 were augmented, and were decreased in the presence of ERK inhibitor or siRNA-ERK. In addition, H9c2 cells exposed to GD exhibited marked increase in LDH release and decreased MTT reduction activity, all of which were not significantly reversed by U0126 treatment. Therefore, the ERK/MAPK signaling pathway may be involved in elevating cardiac Cx43 expression levels under GD in H9c2 cells.

Insulin upregulates GRIM-19 and protects cardiac mitochondrial morphology in type 1 diabetic rats partly through PI3K/AKT signaling pathway

Insulin is involved in the development of diabetic heart disease and is important in the activities of mitochondrial complex I. However, the effect of insulin on cardiac mitochondrial nicotinamide adenine dinucleotide dehydrogenase (ubiquinone) 1 subunit of retinoic-interferon-induced mortality 19 (GRIM-19) has not been characterized. The aim of this study was to investigate the effect of insulin on the mitochondrial GRIM-19 in the hearts of rats with streptozotocin (STZ)-induced type 1 diabetes. Protein changes of GRIM-19 were evaluated by western blotting and reverse transcription-quantitative polymerase chain reaction. Furthermore, the effects of insulin on mitochondrial complex I were detected in HeLa cells and H9C2 cardiac myocytes. During the development of diabetic heart disease, the cardiac function did not change within the 8 weeks, but the mitochondrial morphology was altered. The hearts from the rats with STZ-induced diabetes exhibited reduced expression of GRIM-19. Prior to the overt cardiac dilatation, mitochondrial alterations were already present. Following subcutaneous insulin injection, it was demonstrated that GRIM-19 protein was altered, as well as the mitochondrial morphology. The phosphoinositide 3-kinase inhibitor LY294002 had an effect on insulin signaling in H9C2 cardiacmyocytes, and decreased the level of GRIM-19 by half compared with that in the insulin group. The results indicate that insulin is essential for the control of cardiac mitochondrial morphology and the GRIM-19 expression partly via PI3K/AKT signaling pathways.

Effects of Bariatric Surgery on Serum Bile Acid Composition and Conjugation in a Diabetic Rat Model

BACKGROUND

Serum bile acids (BAs) are elevated following bariatric surgery and have emerged as a potential glucose-lowering beneficial factor. The change of BA components and its underlying mechanisms may be of great significance during bariatric surgery. The aim of this study is to investigate the effects of different bariatric procedures on serum BA composition and explore the potential mechanisms using a diabetic rat model.

METHODS

Duodenal-jejunal bypass (DJB), sleeve gastrectomy (SG), and sham operation were performed in diabetic rats induced by high-fat diet (HFD) and streptozotocin (STZ). Body weight, food intake, oral glucose tolerance test (OGTT), and insulin tolerance test (ITT) were measured at indicated time points. Serum BAs composition and the expression of cholesterol 7α hydroxylase (CYP7A1), bile acid: CoA synthase (BACS) and bile acid-CoA: amino acid N-acyltransferase (BAAT) at both transcriptional and protein levels in the liver were evaluated at 12 weeks postoperatively.

RESULTS

Compared with sham group, DJB and SG both achieved rapid and sustained improvements in glucose tolerance and insulin sensitivity. They also resulted in increased serum BAs, especially the taurine-conjugated BAs by elevated conjugation. No obvious difference was detected between DJB and SG except that SG achieved decreased weight gain and food intake.

CONCLUSIONS

The preferentially elevated serum taurine-conjugated BAs were similar after different bariatric surgeries, and the enhanced conjugation of BAs in the liver might account for the changed serum BAs profiles.

Effects of Low-Dose Recombinant Human Brain Natriuretic Peptide on Anterior Myocardial Infarction Complicated by Cardiogenic Shock

Introduction

The mortality due to cardiogenic shock complicating acute myocardial infarction (AMI) is high even in patients with early revascularization. Infusion of low dose recombinant human brain natriuretic peptide (rhBNP) at the time of AMI is well tolerated and could improve cardiac function.

Objective

The objective of this study was to evaluate the hemodynamic effects of rhBNP in AMI patients revascularized by emergency percutaneous coronary intervention (PCI) who developed cardiogenic shock.

Methods

A total of 48 patients with acute ST segment elevation myocardial infarction (STEMI) complicated by cardiogenic shock and whose hemodynamic status was improved following emergency PCI were enrolled. Patients were randomly assigned to rhBNP (n=25) and control (n=23) groups. In addition to standard therapy, study group individuals received rhBNP by continuous infusion at 0.005 µg kg⁻¹ min⁻¹ for 72 hours.

Results

Baseline characteristics, medications, and peak of cardiac troponin I (cTnI) were similar between both groups. rhBNP treatment resulted in consistently improved pulmonary capillary wedge pressure (PCWP) compared to the control group. Respectively, 7 and 9 patients died in experimental and control groups. No drug-related serious adverse events occurred in either group.

Conclusion

When added to standard care in stable patients with cardiogenic shock complicating anterior STEMI, low dose rhBNP improves PCWP and is well tolerated.

Sleep Deprivation Induced Plasma Amyloid-β Transport Disturbance in Healthy Young Adults

BACKGROUND

Sleep is an important physiological process and beneficial in the removal of brain metabolites and functional recovery. Prior studies have shown that sleep disorders are significant risk factors for Alzheimer's disease (AD).

OBJECTIVE

The present study was designed to characterize the effect of short-term total sleep deprivation (TSD) on plasma amyloid-β (Aβ) concentrations.

METHODS

A clinical trial was conducted between March 1, 2016, and April 1, 2016. Twenty volunteers (age 27.3±3.4 years) with normal cognitive function and sleeping habits were recruited from the local population. Participants underwent 24 h of TSD. Periprocedural blood samples were collected to compare the changes of plasma Aβ42, Aβ40, low-density lipoprotein receptor-related protein (sLRP-1), soluble receptors for advanced glycation end products (sRAGE), and serum superoxide dismutase (SOD) and malonaldehyde (MDA).

RESULTS

TSD increased morning plasma Aβ40 levels by 32.6% (p < 0.001) and decreased the Aβ42/Aβ40 ratio by 19.3% (p < 0.001). A positive relationship was found between TSD duration and plasma Aβ40 level (r = 0.51, p < 0.001) and Aβ40/Aβ42 ratio (r = 0.25, p = 0.003). Plasma concentrations of sLRP1 (p = 0.018) and sRAGE (p = 0.001) decreased significantly after TSD. Aβ40 and Aβ42 plasma concentrations correlated with plasma levels of sLRP1 and sRAGE. Serum SOD decreased after TSD (p = 0.005), whereas serum MDA was increased (p = 0.001).

CONCLUSION

Sleep deprivation can lead to an elevation of plasma Aβ40 and decrease of the Aβ42/Aβ40 ratio. The underlying mechanisms may be related to increased oxidative stress and impaired peripheral Aβ clearance as pathomechanisms of AD.

Protective Effects of Salvianolate on Contrast-Induced Nephropathy after Primary Percutaneous Coronary Intervention: A Prospective Multicenter Randomized Controlled Trial

OBJECTIVES

This study's aim was to evaluate the protective effects of salvianolate on contrast-induced nephropathy after primary percutaneous coronary intervention (PPCI) compared with normal saline (NS) hydration.

METHODS

We enrolled patients with acute myocardial infarction who underwent PPCI in 3 centers in Shanghai. The patients were randomly assigned to the salvianolate group or the NS group. The incidence of CIN, the changes in renal function parameters, and the occurrence of adverse events after the procedure were compared between the 2 groups. We used a multivariate logistic regression analysis to determine the independent correlates of CIN after PPCI.

RESULTS

A total of 484 patients were finally included in the statistical analysis. Compared with the control group, salvianolate reduced the incidence of CIN (9.1 vs. 16.3%, p = 0.018) after PPCI. The renal function parameters after PPCI in the salvianolate group were superior to those of the control group (p < 0.05). The composite adverse events rate was significantly lower in the salvianolate group within 1 month after the procedure (9.5 vs. 15.5%, p = 0.046). A higher peak of troponin I and loop diuretic therapy were the independent correlates of CIN after PPCI.

CONCLUSIONS

Salvianolate reduces the incidence of CIN and protects renal function after PPCI, and the effects were superior to those of NS hydration.

Calcification Remodeling Index Characterized by Cardiac CT as a Novel Parameter to Predict the Use of Rotational Atherectomy for Coronary Intervention of Lesions with Moderate to Severe Calcification

Objective

To assess the feasibility of calcification characterization by coronary computed tomography angiography (CCTA) to predict the use of rotational atherectomy (RA) for coronary intervention of lesions with moderate to severe calcification.

Materials and Methods

Patients with calcified lesions treated by percutaneous coronary intervention (PCI) who underwent both CCTA and invasive coronary angiography were retrospectively included in this study. Calcification remodeling index was calculated as the ratio of the smallest vessel cross-sectional area of the lesion to the proximal reference luminal area. Other parameters such as calcium volume, regional Agatston score, calcification length, and involved calcium arc quadrant were also recorded.

Results

A total of 223 patients with 241 calcified lesions were finally included. Lesions with RA tended to have larger calcium volume, higher regional Agatston score, more involved calcium arc quadrants, and significantly smaller calcification remodeling index than lesions without RA. Receiver operating characteristic curve analysis revealed that the best cutoff value of calcification remodeling index was 0.84 (area under curve = 0.847, p < 0.001). Calcification remodeling index ≤ 0.84 was the strongest independent predictor (odds ratio: 251.47, p < 0.001) for using RA.

Conclusion

Calcification remodeling index was significantly correlated with the incidence of using RA to aid PCI. Calcification remodeling index ≤ 0.84 was the strongest independent predictor for using RA prior to stent implantation.

Upregulation of connexin 43 and apoptosis‑associated protein expression by high glucose in H9c2 cells was improved by resveratrol via the autophagy signaling pathway

The expression of connexin43 (Cx43) protein and the apoptotic rate of cardiomyocytes may be regulated by autophagy and associated with diabetic cardiomyopathy. It is possible that the beneficial effect of resveratrol on diabetic cardiomyocytes occurs via the autophagy pathway. However, it remains to be elucidated whether resveratrol treatment may attenuate the hyperglycemia-induced remodeling of Cx43 and apoptosis through the regulation of autophagy. H9c2 cardiac cells were incubated with 5.5 and 25 mM glucose, 25 mM glucose with chloroquine (50 µM), and 25 mM glucose with or without resveratrol (10, 25 µM) for 24 h. H9c2 cells were also incubated with 25 µM resveratrol in the presence of chloroquine (50 µM). Cell viability was determined using an MTT cell survival assay. Cytotoxicity was determined by quantification of the release of lactate dehydrogenase. The expression of Cx43, autophagic maker proteins [Beclin-1, p62 and microtubule-associated protein 1 light chain 3 (LC3)], apoptosis maker proteins (B-cell lymphoma-2 and Bcl-2 associated X protein), AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) were determined using western blotting. Resveratrol treatment led to reduced Cx43 expression levels compared with the 25 mM glucose treatment and significantly reduced the expression of apoptosis-associated proteins in H9c2 cells under hyperglycemic conditions. Autophagy was increased as indicated by the upregulation of Beclin-1 and p62 expression and the reduced LC3-II/LC3-I ratio. AMPK expression was increased, whereas mTOR expression was reduced in the resveratrol treatment groups. Treatment with chloroquine reversed effect of resveratrol. In conclusion, administration resveratrol may protect H9c2 cells against hyperglycemia-induced Cx43 upregulation and apoptosis, which may be mediated through the induction of the autophagy signaling pathway.

Myocardial Upregulation of Cathepsin D by Ischemic Heart Disease Promotes Autophagic Flux and Protects Against Cardiac Remodeling and Heart Failure

BACKGROUND

Lysosomal dysfunction is implicated in human heart failure for which ischemic heart disease is the leading cause. Altered myocardial expression of CTSD (cathepsin D), a major lysosomal protease, was observed in human heart failure, but its pathophysiological significance has not been determined.

METHODS AND RESULTS

Western blot analyses revealed an increase in the precursor but not the mature form of CTSD in myocardial samples from explanted human failing hearts with ischemic heart disease, which is recapitulated in chronic myocardial infarction produced via coronary artery ligation in Ctsd^+/+ but not Ctsd^+/- mice. Mice deficient of Ctsd displayed impaired myocardial autophagosome removal, reduced autophagic flux, and restrictive cardiomyopathy. After induction of myocardial infarction, weekly serial echocardiography detected earlier occurrence of left ventricle chamber dilatation, greater decreases in ejection fraction and fractional shortening, and lesser wall thickening throughout the first 4 weeks; pressure-volume relationship analyses at 4 weeks revealed greater decreases in systolic and diastolic functions, stroke work, stroke volume, and cardiac output; greater increases in the ventricular weight to body weight and the lung weight to body weight ratios and larger scar size were also detected in Ctsd^+/- mice compared with Ctsd^+/+ mice. Significant increases of myocardial autophagic flux detected at 1 and 4 weeks after induction of myocardial infarction in the Ctsd^+/+ mice were diminished in the Ctsd^+/- mice.

CONCLUSIONS

Myocardial CTSD upregulation induced by myocardial infarction protects against cardiac remodeling and malfunction, which is at least in part through promoting myocardial autophagic flux.

The protective effect of Epimedii Folium and Curculiginis Rhizoma on Alzheimer's disease by the inhibitions of NF-κB/MAPK pathway and NLRP3 inflammasome

The purpose of the current study was to explore the effects of the water extracts of Epimedii Folium and Curculiginis Rhizoma (EX) on Aβ-induced Alzheimer's disease. Aβ1-42 was stereotaxically injected bilaterally into the dorsal hippocampus, and then the rats were orally received EX at the doses of 2 g/kg and 6 g/kg for 30 days. Behavior was monitored through Morris water maze test. The neuroprotective effect of EX were examined with methods of histochemistry and biochemistry. EX reduced the contents of pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) in hippocampus and cortex. EX also reduced the levels of malondialdehyde (MDA) and increased superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and glutathione peroxidase (GSH-Px) in the serum. Immunohistochemical analysis demonstrated that EX inhibited the expressions of NLRP3. In addition, we further confirmed that EX suppressed the expression of the NLRP3 inflammasome. EX inhibited the phosphorylations MAPKs, nuclear factor κB (NF-κB), myeloid differentiation factor 88(MyD88), cathepsin B. In conclusion, these results suggest that EX may be a potential agent for treating Alzheimer's disease.

MicroRNA-181c functions as a protective factor in a 1-methyl-4-phenylpyridinium iodide-induced cellular Parkinson's disease model via BCL2L11

OBJECTIVE

Parkinson is one of the most common neurodegenerative diseases. At present, many studies have pointed out that miRNAs play a very important role in Parkinson's development and process. MiR-181c has been shown to have a significant low expression in blood samples and brain tissues of Parkinson's patients.

MATERIALS AND METHODS

We used 1-Methyl-4-Phenylpyridinium Iodide (MPP(+)) as a tool for constructing the Parkinson's cell model, using mir181c mimics to construct an experimental model of acquisition. The cell viability of PC12 was detected by MTT and CCK8. Reactive oxygen species (ROS) and caspase-3 activity were analyzed. The apoptosis of PC12 was detected by flow cytometry (FCM), and luciferase was used to study the binding of target genes. The protein levels of BCL2L11were measured by Western-blot.

RESULTS

There was a significant low expression of mir181c in MPP(+)-morbid cells. PC12 cell viability was rescued by miR-181c overexpression. Flow cytometry showed that apoptosis in PC12 cells overexpressing miR-181c was significantly decreased. Also, ROS and caspase-3 activity were significantly decreased. Luciferase experiments showed that miR-181c may bind to the 3-'UTR side of BCL2L11 and inhibited its expression. By Western-blot, the BCL2L11 level was markedly decreased by miR-181c.

CONCLUSIONS

miR-181c could promote the cell viability and inhibit the apoptosis of PC12 cells induced by MPP (+) by downregulating BCL2L11, which may play a protective role and provide a new target for PD drug resistance research.

Roles of ST2, IL-33 and BNP in predicting major adverse cardiovascular events in acute myocardial infarction after percutaneous coronary intervention

This study investigated roles of serum ST2, IL-33 and BNP in predicting major adverse cardiovascular events (MACEs) in acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI). Blood samples were collected from the included AMI patients (n = 180) who underwent PCI. All patients were divided into the MACEs and MACEs-free groups. Enzyme-linked immunosorbent assay was performed to measure serum levels of ST2, IL-33 and BNP. Severity of coronary artery lesion was evaluated by Gensini score. Pearson correlation analysis was used. A receiver operating characteristics curve was drawn to evaluate the potential roles of ST2, IL-33 and BNP in predicting MACEs, and Kaplan-Meier curve to analyse the 1-year overall survival rate. Logistic regression analysis was conducted to analyse the independent risk factors for MACEs. Compared with the MACEs-free group, the serum levels of ST2, IL-33 and BNP were significantly higher in the MACEs group. Serum levels of ST2, IL-33 and BNP were positively correlated with each other and positively correlated with Gensini score. The area under curves of ST2, IL-33 and BNP, respectively, were 0.872, 0.675 and 0.902. The relative sensitivity and specificity were, respectively, 76.27% and 85.92%, 69.49% and 58.68%, as well as, 96.61% and 77.69%. Serum levels of ST2, IL-33 and BNP were independent risk factors for MACEs. The 1-year overall survival rate was higher in AMI patients with lower serum levels of ST2, IL-33 and BNP. In conclusion, serum levels of ST2, IL-33 and BNP have potential value in predicting MACEs in AMI patients undergoing PCI.

Identification of Key Gene Modules of Neuropathic Pain by Co-Expression Analysis

Neuropathic pain (NP) is a substantial clinical problem causing great injury to people word-widely. Although gene expression analyses had been performed previously, the mechanisms underlying the etiology and development of NP are still poorly understood. To understand the function genes involved in the etiology and development of NP, we built the co-expression modules and performed function enrichment analysis for neuropathic pain. In the present study, from a public microarray data set (GSE69901) from NCBI, gene co-expression modules were contributed with the help of WGCNA for 12 neuropathic pain samples and 13 control samples, respectively. And functional enrichment analyses were followed by DAVID database. Firstly, we established 21 co-expression modules and 19 co-expression modules out of 5,000 high-express genes in NP and control samples, respectively. Then, it showed great difference in interaction relationships of total genes and hub-genes between pairwise modules, which indicated the high confidence of gene co-expression modules. Finally, functional enrichment analysis of the top five co-expression modules in NP exhibited great differences and significant enrichment in transcription regulation of RNA polymerase II promoter and ubiquitin mediated proteolysis pathway. RNA polymerase II promoter and ubiquitin-mediated proteolysis pathway played important role in etiology and development of NP. Anyhow, our findings provided the framework of gene co-expression modules of NP and furthered the understanding of these modules from functional aspect. J. Cell. Biochem. 118: 4436-4443, 2017. © 2017 Wiley Periodicals, Inc.

Diabetes recurrence after metabolic surgeries correlates with re-impaired insulin sensitivity rather than beta-cell function

AIM

To investigate factors causing diabetes recurrence after sleeve gastrectomy (SG) and duodenal-jejunal bypass (DJB).

METHODS

SG and DJB were performed on rats with diabetes induced by high-fat diet (HFD) and streptozotocin (STZ). HFD was used to induce diabetes recurrence at 4 wk postoperatively. Body weight, oral glucose tolerance test, homeostatic model assessment of insulin resistance (HOMA-IR), insulin signaling [IR, insulin receptor substrate (IRS)1, IRS2, phosphatidylinositol 3-kinase and AKT in liver and skeletal muscle], oral glucose stimulated insulin secretion, beta-cell morphology (mass, apoptosis and insulin secretion), glucagon-like peptide (GLP)-1, PYY and ghrelin were compared among SG rats with common low-fat diet (SG-LFD), SG with HFD (SG-HFD), DJB rats with LFD (DJB-LFD), DJB with HFD (DJB-HFD) and sham-operation with LFD (Sham) at targeted postoperative times.

RESULTS

SG and DJB resulted in significant improvement in glucose tolerance, lower HOMA-IR, up-regulated hepatic and muscular insulin signaling, higher levels of oral glucose-stimulated insulin secretion, bigger beta-cell mass, higher immunofluorescence intensity of insulin, fewer transferase-mediated dUTP-biotin 3’ nick end-labeling (TUNEL)-positive beta cells and higher postprandial GLP-1 and PYY levels than in the Sham group. The improvement in glucose tolerance was reversed at 12 wk postoperatively. Compared with the SG-LFD and DJB-LFD groups, the SG-HFD and DJB-HFD groups showed higher HOMA-IR, down-regulated hepatic and muscular insulin signaling, and more TUNEL-positive beta cells. No significant difference was detected between HFD and LFD groups for body weight, glucose-stimulated insulin secretion, beta-cell mass, immunofluorescence intensity of insulin, and postprandial GLP-1 and PYY levels. Fasting serum ghrelin decreased in SG groups, and there was no difference between HFD-SG and LFD-SG groups.

CONCLUSION

HFD reverses the improvement in glucose homeostasis after SG and DJB. Diabetes recurrence may correlate with re-impaired insulin sensitivity, but not with alterations of beta-cell function and body weight.

[The role of autophagy in the invasion and metastasis of the squamous cell carcinoma of head and neck]

Objective:The aim of this study is to explore the effects of autophagy on the metastasis of the Squamous Cell Carcinoma of Head and Neck (SCCHN) via epithelial to mesenchymal transition (EMT) induced by TGF-β1. Method:Establish the EMT model induced by TGF-β1 in the SCCHN in time/concentration, and the expression of autophagy related protein microtubule associated protein 1 light chain3 (LC3) detected by western blot; Autophagy inhibitor chloroquine (CQ), depressing autophagy, the expression of E-cadherin, cytokeratin, Vimentin and LC3 were examined by Western blot. Wound healing and Transwell invasion assay indicate the effects to metastasis for SCCHN. Result:Autophagy was activated within TGF-β1 induced EMT model in the SCCHN in time/concentration dependently. After autophagy was suppressed, the expression of E-cadherin and cytokeratin increased while vimentin and the capacity of metastasis was reduced compared with control group. Conclusion:TGF-β1 induce EMT and Autophagy in the SCCHN. Autophagy could enhances metastasis in the SCCHN via EMT induced by TGF-β1.

Low-after-high glucose down-regulated Cx43 in H9c2 cells by autophagy activation via cross-regulation by the PI3K/Akt/mTOR and MEK/ERK1/2 signal pathways

PURPOSE

Hypoglycemia in diabetes is a strong predictor of cardiovascular events. High-glucose have been reported to alter connexin43 expression and to promote autophagy in cardiomyocytes. We investigated whether low-after-high glucose would influence connexin43 expression and autophagy in H9c2 cells.

METHODS

H9c2 cells were incubated in 33.3 mM glucose for 24 h followed by 2.5 mM glucose for 2, 4, 6, or 12 h with or without chloroquine (autophagy inhibitor), U0126 (MEK_1/2 inhibitor) or LY294002 (PI3K inhibitor). Cells incubated in 5.5, 33.3, or 2.5 mM glucose with or without inhibitors and in the presence of mannitol were used as controls. Protein expression was assayed by western blot, apoptosis was assayed by flow cytometry, cell proliferation was determined by MTT assays, and cytotoxicity was assayed by lactate dehydrogenase measurement.

RESULTS

Cytotoxicity and early apoptosis were increased and cell proliferation was decreased after exposure to low-after-high glucose, and these results were reversed by chloroquine and U0126 but were aggravated by LY294002. Connexin43 expression was downregulated in a time-dependent manner and was accompanied by upregulated expression of LC3-II, Beclin-1, p62, p-Akt, p-mTOR, and p-ERK_1/2. Chloroquine suppressed autophagy and reversed the downregulation of connexin43. U0126 inhibited ERK activation and decreased autophagy proteins expression but increased connexin43 expression. LY294002 suppressed p-Akt, activated autophagy, and decreased connexin43 expression. Interestingly, MEK_1/2 inhibition also increased p-Akt expression, but inhibition of PI3K led to p-ERK downregulation.

CONCLUSION

Culturing H9c2 cells under low-after-high glucose downregulated connexin43 by promoting autophagy through a mechanism involving the PI3K/Akt/mTOR and MEK/ERK_1/2 signaling pathways.

A Cost-Effective Geodetic Strainmeter Based on Dual Coaxial Cable Bragg Gratings

Observations of surface deformation are essential for understanding a wide range of geophysical problems, including earthquakes, volcanoes, landslides, and glaciers. Current geodetic technologies, such as global positioning system (GPS), interferometric synthetic aperture radar (InSAR), borehole and laser strainmeters, are costly and limited in their temporal or spatial resolutions. Here we present a new type of strainmeters based on the coaxial cable Bragg grating (CCBG) sensing technology that provides cost-effective strain measurements. Two CCBGs are introduced into the geodetic strainmeter: one serves as a sensor to measure the strain applied on it, and the other acts as a reference to detect environmental noises. By integrating the sensor and reference signals in a mixer, the environmental noises are minimized and a lower mixed frequency is obtained. The lower mixed frequency allows for measurements to be taken with a portable spectrum analyzer, rather than an expensive spectrum analyzer or a vector network analyzer (VNA). Analysis of laboratory experiments shows that the strain can be measured by the CCBG sensor, and the portable spectrum analyzer can make measurements with the accuracy similar to the expensive spectrum analyzer, whose relative error to the spectrum analyzer R3272 is less than ±0.4%. The outputs of the geodetic strainmeter show a linear relationship with the strains that the CCBG sensor experienced. The measured sensitivity of the geodetic strainmeter is about -0.082 kHz/με; it can cover a large dynamic measuring range up to 2%, and its nonlinear errors can be less than 5.3%.

[Effects of long-term fertilization on soil fertility in yellow fluvo-aquic soil]

Based on the long-term field fertilization experiment in yellow fluvo-aquic soil, this study selected 2 types of soil physical, 8 items of soil chemical, and 5 soil biological properties for principal component-cluster analysis to valuate comprehensively effects of long-term fertilization on soil fertility. Results showed that significant differences of soil properties were found among the fertilization treatments. Compared with no organic manure treatment (NPK), all treatments of organic manure (M) or its combination with inorganic fertilizers (MN, MNP, MNPK) significantly reduced soil bulk density, and increased soil total porosity, the contents of soil organic carbon, total nitrogen, alkali-hydrolyzable nitrogen, available phosphorus, microbial biomass, and activities of catalase, urease, alkaline phosphatase and invertase. Two principal components that could reflect 85.5% of the original information quantity without losing any original variables were extracted from the initial 15 indices. Within the primary group of principal components, bulk density, total porosity, organic matter, total nitrogen, alkali-hydrolyzable nitrogen, total phosphorous, available phosphorus, available potassium,microbial biomass, catalase, urease, alkaline phosphatase and inver-tase were the major contributors, while among the secondary group of principal components, total potassium and pH were the major ones. Hierarchical cluster analysis of the new indices extracted based on scores of the two principal components revealed the effects of different patterns of long-term fertilization displayed an order of MNPK＞MNP＞M, MN＞NPK＞N, NP＞CK. In conclusion, organic fertilizer has the positive effect on improving soil fertility, and combined application of organic and N, P, K fertilizer is the best fertilizing model.

Intermedin1‑53 enhances angiogenesis and attenuates adverse remodeling following myocardial infarction by activating AMP‑activated protein kinase

Adverse ventricular remodeling is a maladaptive response to acute loss of myocardium and an important risk factor for heart failure following myocardial infarction (MI). Intermedin (IMD) is a novel member of the calcitonin/calcitonin gene‑related peptide family, which may possess potent cardioprotective properties. The aim of the present study was to determine whether IMD1‑53, a mature bioactive form of IMD, may promote therapeutic angiogenesis within the infarcted myocardium, therefore attenuating adverse ventricular remodeling post‑MI. The present study observed that treatment with IMD1‑53 promoted proliferation, migration and tube formation of primary cultured myocardial microvascular endothelial cells (MMVECs). In a rat model of MI, chronic administration of IMD1‑53 increased capillary density in the peri‑infarct zone, attenuated ventricular remodeling and improved cardiac performance post‑MI. Treatment with IMD1‑53 also significantly increased the expression levels of phosphorylated‑AMP‑activated protein kinase (AMPK) and the subsequent activation of endothelial nitric oxide synthase in MMVECs and post‑MI rat myocardium, without a significant influence on the expression of vascular endothelial growth factor. Notably, the in vitro effects of IMD1‑53 on angiogenesis and the in vivo effects of IMD1‑53 on post‑MI ventricular remodeling were largely abrogated by the co‑administration of compound C, an AMPK inhibitor. In conclusion, the present study demonstrated that IMD1‑53 could attenuate adverse ventricular remodeling post‑MI via the promotion of therapeutic angiogenesis, possibly through the activation of AMPK signaling.

Novel AlN/Pt/ZnO Electrode for High Temperature SAW Sensors

In order to develop a film electrode for the surface acoustic wave (SAW) devices working in high temperature, harsh environments, novel AlN/Pt/ZnO multilayers were prepared using pulsed laser deposition (PLD) systems on langasite (LGS) substrates. The AlN film was used as a protective layer and the ZnO buffer layer was introduced to improve the crystal quality of Pt films. The results show that the resistances of Pt and AlN/Pt film electrodes violently increase above 600 °C and 800 °C, respectively, while the resistances of AlN/Pt/ZnO electrodes have more stable electrical resistance from room temperature to 1000 °C. The AlN/Pt/ZnO electrode, where the ZnO film was deposited at 600 °C, has the best temperature stability and can steadily work for 4 h at 1000 °C. The mechanism underlying the stable resistance of the AlN/Pt/ZnO electrode at a high temperature was investigated by analyzing the microstructure of the prepared samples. The proposed AlN/Pt/ZnO film electrode has great potential for applications in high temperature SAW sensors.

[Clinical analysis of 12 patients with pediatric antiphospholipid syndrome with pulmonary embolism]

Objective: To identify the clinical and immunological characteristics of pediatric antiphospholipid syndrome (APS) patients with pulmonary embolism. Method: Among 47 pediatric APS patients from Peking Union Medical College Hospital during the year of 2000 to 2015, 12 patients were diagnosed of pulmonary embolism, who were investigated and compared with APS patients without pulmonary embolism. Result: Twelve patients (among whom 6 cases were primary and the other 6 were secondary APS)had pulmonary embolism and all of them were non-shock type, which was the first presenting manifestation in 6 of them.Eight cases were misdiagnosed as infection, while 3 cases were missed.Among patients with pulmonary embolism, 10 patients suffered from deep vein thrombosis at the same time, mainly in lower extremities.2 cases had thrombotic recurrence, which happened only in primary APS patients, because of irregular monitoring of International Normalized Ratio, or not taking aspirin after quitting warfarin.Positive anticardiolipin (ACL) and lupus anticoagulant (LA) were found in 10 and 9 patients respectively.Four primary APS patients had positive anti-nuclear antibodies (ANA). During follow-up of 3-100 months (median 23 months) of primary APS, no one had evolved manifestations of systemic lupus erythematosus.Primary APS was more often seen in males (M∶F 5∶1 vs. 0∶6) and the patients were much younger ((15±1) vs. (17±0) years old) than those with secondary APS.Besides that, no statistically significant difference was seen between primary and secondary APS (P all>0.05). Compared with APS patients without pulmonary embolism, pulmonary hypertension was more common in patients suffered from pulmonary embolism (3/12 vs. 0, P<0.05). Conclusion: Pulmonary embolism can be the first symptom in pediatric APS patients and all of them are non-shock type, which tends to be misdiagnosed or missed. A majority of them suffer from deep vein thrombosis in the lower extremities.Rethrombosis takes place when the anticoagulant therapy is irregular.Positive anti-nuclear antibodies can be seen in primary APS patients, but no manifestations of lupus come out during follow-up.There is no significant difference between primary APS and secondary APS.Pulmonary hypertension is more common in APS patients suffered from pulmonary embolism.

Autophagy was involved in the protective effect of metformin on hyperglycemia-induced cardiomyocyte apoptosis and Connexin43 downregulation in H9c2 cells

Background: Increased cardiomyocyte apoptosis under high glucose condition contributes to diabetic cardiomyopathy. Degradation of cardiac Connexin43 (Cx43) has been associated with cardiac dysfunction in diabetic heart. Clinical and experimental studies suggested that metformin (Met) exhibits cardioprotective properties against diabetes. Aim: The aim of this study was to investigate the effect and underlying signaling mechanisms of metformin on apoptosis and Cx43 expression in H9c2 cells presenting with hyperglycemia conditions. Methods: In the present study, H9c2 cardiac cells were incubated with 5.5 mM glucose, 33.3 mM glucose, 33.3 mM glucose with metformin at two dose (100 μM, 1 mM) for 96 hours, and 1 mM metformin with chloroquine (50 μM) in 33.3 mM glucose medium. Cell viability was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) cell survival assay. Cytotoxicity was determined by the release of lactate dehydrogenase (LDH). The expression of Cx43, autophagic maker protein (LAMP-1, Beclin-1, p62 and LC3) and apoptosis maker protein (Bcl-2 and Bax) were determined by western blot. Results: The results showed that high glucose increased apoptosis and decreased Cx43 expression. Interestingly, metformin attenuated hyperglycemia-increased apoptosis and restored Cx43 expression. Moreover, this treatment caused autophagy as well, which indicated by up-regulation of autophagy-related proteins LAMP-1, Beclin-1, p62 and reduction in the ratio of LC3-II/LC3-I. In addition, administration autophagy inhibitor chloroquine (CQ) did not block the effect of metformin on Cx43 expression while increasing Cx43 content, together with an increased apoptosis. Conclusion: Administration metformin can protect the H9c2 cells against hyperglycemia-induced apoptosis and Cx43 down-regulation, in part, mediated through the induction of autophagy pathway.

Discovery of natural mouse serum derived HIV-1 entry inhibitor(s)

Among rationally designed human immunodeficiency virus 1 (HIV-1) inhibitors, diverse natural factors have showed as potent anti-HIV activity in human blood. We have discovered that the boiled supernatant of healthy mouse serum could suppress HIV-1 entry, and exhibited reduced inhibitory activity after trypsin digestion. Further analysis demonstrated that only the fraction containing 10-25 K proteins could inhibit HIV-1 mediated cell-cell fusion. These results suggest that the 10-25 K protein(s) is novel natural HIV-1 entry inhibitor(s). Our findings provide important information about novel natural HIV entry inhibitors in mouse serum.