Calycosin protects against oxidative stress-induced cardiomyocyte apoptosis by activating aldehyde dehydrogenase 2.

Myocardial infarction (MI) is the leading cause of death worldwide, and oxidative stress is part of the process that causes MI. Calycosin, a naturally occurring substance with cardioprotective properties, is one of the major active constituents in Radix Astragali. In this study, effect of Calycosin was investigated in vivo and in vitro to determine whether it could alleviate oxidative stress and oxidative stress-induced cardiac apoptosis in neonatal cardiomyocytes (NCMs) via activation of aldehyde dehydrogenase 2 (ALDH2). Calycosin protected against oxidative stress and oxidative stress-induced apoptosis in NCMs. Molecular docking revealed that the ALDH2-Calycosin complex had a binding energy of -9.885 kcal/mol. In addition, molecular docking simulations demonstrated that the ALDH2-Calycosin complex was stable. Using BLI assays, we confirmed that Calycosin could interact with ALDH2 (KD  = 1.9 × 10-4 M). Furthermore, an ALDH2 kinase activity test revealed that Calycosin increased ALDH2 activity, exhibiting an EC50 of 91.79 µM. Pre-incubation with ALDH2 inhibitor (CVT-10216 or disulfiram) reduced the cardio-protective properties Calycosin. In mice with MI, Calycosin therapy substantially reduced myocardial apoptosis, oxidative stress, and activated ALDH2. Collectively, our findings clearly suggest that Calycosin reduces oxidative stress and oxidative stress-induced apoptosis via the regulation of ALDH2 signaling, which supports potential therapeutic use in MI.

ERß induces the differentiation of cultured osteoblasts by both Wnt/ß-catenin signaling pathway and estrogen signaling pathways.

Although 17ß-estradial (E2) is known to stimulate bone formation, the underlying mechanisms are not fully understood. Recent studies have implicated the Wnt/ß-catenin pathway as a major signaling cascade in bone biology. The interactions between Wnt/ß-catenin signaling pathway and estrogen signaling pathways have been reported in many tissues. In this study, E2 significantly increased the expression of ß-catenin by inducing phosphorylations of GSK3ß at serine 9. ERß siRNAs were transfected into MC3T3-E1 cells and revealed that ERß involved E2-induced osteoblasts proliferation and differentiation via Wnt/ß-catenin signaling. The osteoblast differentiation genes (BGP, ALP and OPN) and proliferation related gene (cyclin D1) expression were significantly induced by E2-mediated ERß. Furthermore immunofluorescence and immunoprecipitation analysis demonstrated that E2 induced the accumulation of ß-catenin protein in the nucleus which leads to interaction with T-cell-specific transcription factor/lymphoid enhancer binding factor (TCF/LEF) transcription factors. Taken together, these findings suggest that E2 promotes osteoblastic proliferation and differentiation by inducing proliferation-related and differentiation-related gene expression via ERß/GSK-3ß-dependent Wnt/ß-catenin signaling pathway. Our findings provide novel insights into the mechanisms of action of E2 in osteoblastogenesis.

Estradiol via estrogen receptor beta inhibits chondrogenesis of mouse vertebral growth plate in vitro.

PURPOSE: Abnormal growth of vertebral growth plate (VGP) was considered as one of the etiologic factors in adolescent idiopathic scoliosis (AIS). Previous studies described that estrogen played an important role in the pathogenesis of AIS. The present study was aimed to investigate the effect of estrogen/estrogen receptor axis on mouse VGP chondrocytes in vitro. METHODS: Chondrocytes were isolated from mouse VGP and treated with or without 17ß-estradiol (E2). Cell proliferation was measured by the cell growth rate assay. Gene expression of collagen type II and aggrecan were evaluated by real-time PCR. Expression of the proliferating cell nuclear antigen (PCNA), Sox9, and Smad4 were detected by Western blotting. RESULTS: Estradiol inhibited the proliferation of VGP chondrocytes and the gene expression of collagen type II and aggrecan and downregulated the protein expression of PCNA, Sox9, and Smad4. In addition, the inhibitory effect of estradiol was reversed by ERß small interfering RNA (siRNA) or PHTPP, an ERß antagonist. CONCLUSIONS: Estradiol via estrogen/estrogen receptor ß axis inhibits the proliferation and differentiation of VGP chondrocytes, which might give some new insight into the regulatory mechanism of bone development.

A modified surgical procedure for congenital kyphoscoliosis: selective partial hemivertebrectomy via posterior-only approach.

OBJECTIVES: The study aims to assess the correction efficacy of selective partial hemivertebra excision via posterior-only approach for adolescent patients with congenital kyphoscoliosis. METHODS: A total of 17 cases (10 M/7 F) were enrolled to this study, all of whom were fully segmented hemivertebra. The mean grade of Risser sign was 1.82 ± 1.07. The average time of follow-up was 20.12 ± 6.88 months. Patients were all treated with selective partial hemivertebra excision and instrumentation via posterior-only approach. The maximal coronal Cobb angle, segmental curves, and segmental kyphotic curves are measured before and after operation, and at the latest follow-up. The data was analyzed to evaluate the correction efficacy. RESULTS: There were no postoperative infections and no neurological complications in all patients. The mean size of the segmental curve was 38.65 ± 5.35° before operation and 13.55 ± 1.82° after operation, with a mean correction of 25.10 ± 5.44°, which turned to 16.59 ± 2.14° at latest follow-up. The mean maximal coronal Cobb angle was 42.90 ± 7.96° before operation, 14.68 ± 2.44° after operation, and 17.50 ± 2.64° at the latest follow-up, giving a correction of 65.7%. The correction rate of segmental kyphotic curve was 72.6%, as the mean segmental kyphotic angle was 22.64 ± 6.74° before operation, 6.15 ± 2.50° after operation, and 6.9° at the latest follow-up, with a loss of 6.90 ± 2.68°. CONCLUSIONS: For the patients whose congenital kyphoscoliosis are due to hemivertebrae, selective partial hemivertebra excision and instrumentation via posterior-only approach is recommended to those ranging from 9 to 14 years old, with the Risser sign range grades 0-3 and Cobb angles <60°. This individualized treatment can balance the growth on the two sides of the spine and achieve satisfactory therapeutic effect through removing excrescent growth center.

Przewaquinone A inhibits Angiotensin II-induced endothelial diastolic dysfunction activation of AMPK.

BACKGROUND: Endothelial dysfunction (ED), characterized by markedly reduced nitric oxide (NO) bioavailability, vasoconstriction, and a shift toward a proinflammatory and prothrombotic state, is an important contributor to hypertension, atherosclerosis, and other cardiovascular diseases. Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) is widely involved in cardiovascular development. Przewaquinone A (PA), a lipophilic diterpene quinone extracted from Salvia przewalskii Maxim, inhibits vascular contraction. PURPOSE: Herein, the goal was to explore the protective effect of PA on ED in vivo and in vitro, as well as the underlying mechanisms. METHODS: A human umbilical vein endothelial cell (HUVEC) model of ED induced by angiotensin II (AngII) was used for in vitro observations. Levels of AMPK, endothelial nitric oxide synthase (eNOS), vascular cell adhesion molecule-1 (VCAM-1), nitric oxide (NO), and endothelin-1 (ET-1) were detected by western blotting and ELISA. A mouse model of hypertension was established by continuous infusion of AngII (1000 ng/kg/min) for 4 weeks using osmotic pumps. Following PA and/or valsartan administration, NO and ET-1 levels were measured. The levels of AMPK signaling-related proteins in the thoracic aorta were evaluated by immunohistochemistry. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were measured using the tail cuff method. Isolated aortic vascular tone measurements were used to evaluate the vasodilatory function in mice. Molecular docking, molecular dynamics, and surface plasmon resonance imaging (SPRi) were used to confirm AMPK and PA interactions. RESULTS: PA inhibited AngII-induced vasoconstriction and vascular adhesion as well as activated AMPK signaling in a dose-dependent manner. Moreover, PA markedly suppressed blood pressure, activated vasodilation in mice following AngII stimulation, and promoted the activation of AMPK signaling. Furthermore, molecular simulations and SPRi revealed that PA directly targeted AMPK. AMPK inhibition partly abolished the protective effects of PA against endothelial dysfunction. CONCLUSION: PA activates AMPK and ameliorates endothelial dysfunction during hypertension.

Radix Glycyrrhizae extract and licochalcone a exert an anti-inflammatory action by direct suppression of toll like receptor 4.

ETHNOPHARMACOLOGICAL RELEVANCE: Radix Glycyrrhizae (GL), a herbal medicine that is widely available, has shown advantages for a variety of inflammatory diseases. Toll like receptor 4 (TLR4) pathway has been shown to play a key role in the progression of inflammation. AIM OF THE STUDY: The purpose of this study was to investigate the involvement of TLR4 in the anti-inflammatory mechanism of GL extract and its active constituent on acute lung injury (ALI). MATERIALS AND METHODS: A model of inflammation produced by lipopolysaccharide (LPS) was established in C57BL/6 mice and macrophages derived from THP-1. To screen the active components of GL, molecular docking was used. Molecular dynamics and surface plasmon resonance imaging (SPRi) were used to study the interaction of a specific drug with the TLR4-MD2 complex. TLR4 was overexpressed by adenovirus to confirm TLR4 involvement in the anti-inflammatory activities of GL and the chosen chemical. RESULTS: We observed that GL extract significantly reduced both LPS-induced ALI and the production of pro-inflammatory factors including TNF-α, IL-6 and IL-1ß. Additionally, GL inhibited the binding of Alexa 488-labeled LPS (LPS-488) to the membrane of THP-1 derived macrophages. GL drastically reduce on the expression of TLR4 and the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor-B (NF-κB). Furthermore, molecular docking revealed that Licochalcone A (LicoA) docked into the LPS binding site of TLR4-MD2 complex. MD2-LicoA binding conformation was found to be stable using molecular dynamic simulations. SPRi indicated that LicoA bound to TLR4-MD2 recombinant protein with a KD of 3.87 × 10-7 M. LicoA dose-dependently reduced LPS-488 binding to the cell membrane. LicoA was found to significantly inhibit LPS-induced lung damage and inflammation. Furthermore, LicoA inhibited TLR4 expression, MAPK and NF-κB activation in a dose-dependent manner. The inhibitory effects of GL and LicoA on LPS-induced inflammation and TLR4 signaling activation were partly eliminated by TLR4 overexpression. CONCLUSION: Our findings imply that GL and LicoA exert inhibitory effects on inflammation by targeting the TLR4 directly.

Ethyl ferulate suppresses post-myocardial infarction myocardial fibrosis by inhibiting transforming growth factor receptor 1.

BACKGROUND: With an increasing number of myocardial infarction (MI) patients, myocardial fibrosis is becoming a widespread health concern. It's becoming more and more urgent to conduct additional research and investigations into efficient treatments. Ethyl ferulate (EF) is a naturally occurring substance with cardioprotective properties. However, the extent of its impact and the underlying mechanism of its treatment for myocardial fibrosis after MI remain unknown. PURPOSE: The goal of this study was to look into how EF affected the signaling of the TGF-receptor 1 (TGFBR1) in myocardial fibrosis after MI. METHODS: Echocardiography, hematoxylin-eosin (HE) and Masson trichrome staining were employed to assess the impact of EF on heart structure and function in MI-affected mice in vivo. Cell proliferation assay (MTS), 5-Ethynyl-2'-deoxyuridine (EdU), and western blot techniques were employed to examine the influence of EF on native cardiac fibroblast (CFs) proliferation and collagen deposition. Molecular simulation and surface plasmon resonance imaging (SPRi) were utilized to explore TGFBR1 and EF interaction. Cardiac-specific Tgfbr1 knockout mice (Tgfbr1ΔMCK) were utilized to testify to the impact of EF. RESULTS: In vivo experiments revealed that EF alleviated myocardial fibrosis, improved cardiac dysfunction after MI and downregulated the TGFBR1 signaling in a dose-dependent manner. Moreover, in vitro experiments revealed that EF significantly inhibited CFs proliferation, collagen deposition and TGFBR1 signaling followed by TGF-ß1 stimulation. More specifically, molecular simulation, molecular dynamics, and SPRi collectively showed that EF directly targeted TGFBR1. Lastly, knocking down of Tgfbr1 partially reversed the inhibitory activity of EF on myocardial fibrosis in MI mice. CONCLUSION: EF attenuated myocardial fibrosis post-MI by directly suppressing TGFBR1 and its downstream signaling pathway.

Detection of Pseudomonas aeruginosa using a wireless magnetoelastic sensing device.

This paper describes the real-time quantification of Pseudomonas aeruginosa (P. aeru) concentrations using a wireless magnetoelastic sensing device. The sensor is fabricated by coating a magnetoelastic ribbon with a polyurethane protecting film. In response to an externally applied time varying magnetic field, the magnetoelastic sensor vibrates at a resonance frequency that can be remotely determined by monitoring the magnetic flux emitted by the sensor. The resonance frequency changes in response to properties changes of a liquid culture medium and bacteria adhesion to the sensor as P. aeru consumes nutrients from the culture medium in growth and reproduction. The effects of properties (conductivity, viscosity, mass) are investigated with quartz crystal microbalance (QCM), microscopy imaging, and conductivity measurement. Using the described technique we are able to directly quantify P. aeru concentrations of 10(3) to 10(8)cells/ml, with a detection limit of 10(3)cells/ml at a noise level of approximately 20 Hz. The lack of any physical connections between the sensor and the monitoring electronics facilitates aseptic operation, and makes the sensor platform ideally suited for monitoring bacteria from within, for example, sealed food containers.

A rapid highly-sensitive endotoxin detection system.

This paper presents a rapid, highly-sensitive, and low-cost method of endotoxin quantification based on the use of stress-responsive magnetoelastic sensors, that monitor the gel formation (viscosity change) of the Limulus Amoebocyte Lysate (LAL) assay in response to endotoxin. Ribbon-like magnetoelastic sensors, 12.7 mm x 6 mm x 28 microm, were immersed in a LAL assay after mixing with test samples of variable endotoxin concentration, and the decrease in resonance amplitude of the sensor was recorded as a function of time. Experimental results show excellent correlation between endotoxin concentration and the maximum clot rate, determined by taking the minimum point of the first derivative of the amplitude-time curve, as well as the clotting-time, defined as the time that corresponds to the maximum clot rate. Using a LAL gel-clot assay with a sensitivity of 0.06 EU/ml (EU: endotoxin unit), the magnetoelastic sensor based technology can detect the presence of endotoxin at 0.0105 EU/ml in test requiring approximately 20 min. Unlike optical methods used for determining endotoxin concentration, the color of the test solution does not impact the magnetoelastic sensor measurement. Due to the small size of the sensor reader electronics and low cost, the magnetoelastic sensor based endotoxin detection system is ideally suited for wide-spread use in endotoxin screening for sepsis prevention.

Debridement, internal fixation, and reconstruction using titanium mesh for the surgical treatment of thoracic and lumbar spinal tuberculosis via a posterior-only approach: a 4-year follow-up of 28 patients.

BACKGROUND: The standard recommended method for surgical treatment of spinal tuberculosis is an anterior approach for debridement and fusion combined with posterior instrumentation. However, the method has its disadvantages. The aim of this study was to analyze the effectiveness and safety of treating thoracic and lumbar spinal tuberculosis with debridement, internal fixation reconstruction, and using specially formed titanium mesh cages via a posterior-only approach. METHODS: The authors retrospectively reviewed the cases of 28 patients with spinal tuberculosis treated by debridement, internal fixation, and reconstruction with a specially formed titanium mesh cage via a posterior-only approach. The levels involved were less than two contiguous vertebrae: 13 thoracic vertebrae, 5 thoracolumbar vertebrae, and 10 lumbar vertebrae. All patients suffered from back pain, and nine patients had neurologic deficits (two were class C and seven were in class D according to the American Spinal Injury Association classification). All patients were followed up every 3 months after surgery, with a minimum 48-month follow-up. The clinical efficacy was evaluated based on the visual analog scale (VAS), the Oswestry Disability Index (ODI), neurological status, kyphosis angle, and erythrocyte sedimentation rate (ESR). RESULTS: All patients obtained solid bony fusions without failure of fixation. The infections were resolved in all patients, as noted by normalization of their ESR. The average surgery time was 2 h and 15 min, with an average blood loss of 435 ml. The VAS scores dropped from a preoperative level of 6.31 ± 1.25 to the final follow-up level of 0.57 ± 0.14. The ODI scores dropped from 39.14 ± 12.38 preoperatively to 7.29 ± 3.09 at 1 year postoperatively and 6.77 ± 2.53 at final follow-up. The kyphosis Cobb's angle was corrected from 22.31° ± 4.26° preoperatively to 5.86° ± 0.57° at final follow-up. No subsidence of titanium mesh cage or posterior instrumentation failure was observed postoperatively. The neurological outcome increased by 1-2 grades in the patients with neurological deficits. CONCLUSIONS: Debridement, internal fixation, and reconstruction using specially formed titanium mesh cages via a posterior-only approach is effective and safe for treating adults with thoracic and lumbar spinal tuberculosis involving less than two contiguous levels.

A staphylococcal enterotoxin B magnetoelastic immunosensor.

A magnetoelastic immunosensor for detection of staphylococcal enterotoxin B (SEB) is described. The magnetoelastic sensor is a newly developed mass/elasticity-based transducer of high sensitivity having a material cost of approximately $0.001/sensor. Affinity-purified rabbit anti-SEB antibody was covalently immobilized on magnetoelastic sensors, of dimensions 6 mm x 2 mm x 28 microm. The affinity reaction of biotin-avidin and biocatalytic precipitation are used to amplify antigen-antibody binding events on the sensor surface. Horseradish peroxidase (HRP) and alkaline phosphatase were examined as the labeled enzymes to induce biocatalytic precipitation. The alkaline phosphatase substrate, 5-bromo-4-chloro-3-indolyl phosphate (BCIP) produces a dimer, which binds tightly to the sensor surface, inducing a change in sensor resonance frequency. The biosensor demonstrates a linear shift in resonance frequency with staphylococcal enterotoxin B concentration between 0.5 and 5 ng/ml, with a detection limit of 0.5 ng/ml.

A magnetoelastic bioaffinity-based sensor for avidin.

A magnetoelastic bioaffinity sensor coupled with biocatalytic precipitation is described for avidin detection. The non-specific adsorption characteristics of streptavidin on different functionalized sensor surfaces are examined. It is found that a biotinylated poly(ethylene glycol) (PEG) interface can effectively block non-specific adsorption of proteins. Coupled with the PEG immobilized sensor surface, alkaline phosphatase (AP) labeled streptavidin is used to track specific binding on the sensor. This mass-change-based signal is amplified by the accumulation on the sensor of insoluble products of 5-bromo-4-chloro-3-indolyl phosphate catalyzed by AP. The resulting mass loading on the sensor surface in turn shifts the resonance frequency of the magnetoelastic sensors, with an avidin detection limit of approximately 200 ng/ml.

The clinical outcomes of surgical treatment of noncontiguous spinal tuberculosis: a retrospective study in 23 cases.

STUDY DESIGN: A retrospective clinical study. OBJECTIVE: To evaluate the clinical efficacy of the surgical treatment of noncontiguous spinal tuberculosis (NSTB), and to discuss its therapeutic strategies. METHODS: We performed a retrospective review of clinical and radiographic data that were prospectively collected on 550 consecutive spinal tubercular patients including 27 patients who were diagnosed and treated as NSTB in our institution from June 2005 to June 2011. Apart from 4 patients being treated conservatively, the remainder received surgery by posterior transforaminal debridement, interbody fusion with instrumentation, posterior instrumentation and anterior debridement with fusion in a single or two-stage operation. The clinical outcomes were evaluated before and after treatment in terms of hematologic and radiographic examinations, bone fusion and neurologic status. The Oswestry Disability Index score was determined before treatment and at the last follow-up visit. RESULTS: 23 patients (15 M/8F), averaged 44.6 ± 14.2 years old (range, 19 to 70 yd), who received surgical treatment, were followed up after surgery for a mean of 52.5 ± 19.5 months (range, 24 to 72 months). The kyphotic angle was changed significantly between pre- and postoperation (P<0.05). The mean amount of correction was 12.6 ± 7.2 degrees, with a small loss of correction at last follow-up. All patients achieved solid bone fusion. No patients with neurological deficit deteriorated postoperatively. Neither mortalities nor any major complications were found. There was a significant difference of Oswestry Disability Index scores between preoperation and the final follow-up. CONCLUSION: The outcomes of follow-up showed that posterior and posterior-anterior surgical treatment methods were both viable surgical options for NSTB. Posterior transforaminal debridement, interbody fusion and posterior instrumentation, as a less invasive technique, was feasible and effective to treat specific tubercular foci.

A wireless magnetoelastic biosensor for the direct detection of organophosphorus pesticides.

An organophosphorus (OP) pesticide sensor was fabricated by applying a pH-sensitive polymer coating and organophosphorus hydrolase (OPH) enzyme onto the surface of a magnetoelastic sensor, the magnetic analogue of the better-known surface acoustic wave sensor. Organophosphorus hydrolase catalyses the hydrolysis of a wide range of organophosphorus compounds, which changes the pH in the hydrogel. This article describes the application of the magnetoelastic sensor for the detection of OP pesticides by measuring the changes in viscoelasticity caused by the swelling/shrinking of the pH-responsive polymer when exposed to the pesticides. The sensor was successfully used to detect paraoxon and parathion down to a concentration of 1 x 10(-7) and 8.5 x 10(-7) M respectively.

A wireless, remote query glucose biosensor based on a pH-sensitive polymer.

This paper describes a wireless, remote query glucose biosensor using a ribbonlike, mass-sensitive magnetoelastic sensor as the transducer. The glucose biosensor is fabricated by first coating the magnetoelastic sensor with a pH-sensitive polymer and upon it a layer of glucose oxidase (GOx). The pH-responsive polymer swells or shrinks, thereby changing mass, respectively, in response to increasing or decreasing pH values. The GOx-catalyzed oxidation of glucose produces gluconic acid, inducing the pH-responsive polymer to shrink, which in turn decreases the polymer mass. In response to a time-varying magnetic field, a magnetoelastic sensor mechanically vibrates at a characteristic resonance frequency, the value of which inversely depends on sensor mass loading. As the magnetoelastic films are magnetostrictive, the vibrations launch magnetic flux that can be remotely detected using a pickup coil. Hence, changes in the resonance frequency of a passive magnetoelastic transducer are detected on a remote query basis, without the use of physical connections to the sensors.The sensitivity of the glucose biosensors decreases with increasing ionic strength; at physiological salt concentrations, 0.6 mmol/L of glucose can be measured. At glucose concentrations of 1-10 mmol/L, the biosensor response is reversible and linear, with the detection limit of 0.6 mmol/L corresponding to an error in resonance frequency determination of 20 Hz. Since no physical connections between the sensor and the monitoring instrument are required, this sensor can potentially be applied to in vivo and in situ measurement of glucose concentrations.

Magnetoelastic immunosensors: amplified mass immunosorbent assay for detection of Escherichia coli O157:H7.

A mass-sensitive magnetoelastic immunosensor for detection of Escherichia coli O157:H7 is described, based on immobilization of affinity-purified antibodies attached to the surface of a micrometer-scale magnetoelastic cantilever. Alkaline phosphatase is used as a labeled enzyme to the anti-E. coli O157:H7 antibody, amplifying the mass change associated with the antibody-antigen binding reaction by biocatalytic precipitation of 5-bromo-4-chloro-3-indolyl phosphate in a pH 10.0 PBS solution. The detection limit of the biosensor is 10(2) E. coli O157:H7 cells/mL. A linear change in the resonance frequency of the biosensor was found to E. coli O157:H7 concentrations ranging from 10(2) to 10(6) cells/mL.