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1.
Enzyme Microb Technol ; 132: 109443, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31731969

RESUMO

l-Ribose is an important pharmaceutical intermediate that is used in the synthesis of numerous antiviral and anticancer drugs. However, it is a non-natural and expensive rare sugar. Recently, the enzymatic synthesis of l-ribose has attracted considerable attention owing to its considerable advantages over chemical approaches. In this work, a new strategy was developed for the production of l-ribose from the inexpensive starting material l-arabinose. The l-arabinose isomerase (l-AIase) gene from Alicyclobacillus hesperidum and the d-lyxose isomerase (d-LIase) gene from Thermoflavimicrobium dichotomicum were cloned and co-expressed in Escherichia coli, resulting in recombinant cells harboring the vector pCDFDuet-Alhe-LAI/Thdi-DLI. The co-expression system exhibited optimal activity at a temperature of 70 °C and pH 6.0, and the addition of Co2+ enhanced the catalytic activity by 27.8-fold. The system containing 50 g L-1 of recombinant cells were relatively stable up to 55 °C. The co-expression system (50 g L-1 of recombinant cells) afforded 20.9, 39.7, and 50.3 g L-1 of l-ribose from initial l-arabinose concentrations of 100, 300, and 500 g L-1, corresponding to conversion rate of 20.9%, 13.2%, and 10.0%, respectively. Overall, this study provides a viable approach for producing l-ribose from l-arabinose under slightly acidic conditions using a co-expression system harboring l-AIase and d-LIase genes.

2.
Talanta ; 207: 120313, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31594600

RESUMO

Peptidomics research is of great significance for discovering potential biomarkers and monitoring human diseases. As a kind of common clinical biofluid, saliva known for its noninvasive collection and easy accessibility has been widely used in peptidomics research. In this article, we combined immobilized metal ions affinity chromotography (IMAC) with mesoporous material and proposed the copper ion doped magnetic mesoporous silica material (denoted as Fe3O4@mSiO2-Cu2+) which had a large surface area of 221 m2 g-1 and pore volume of 0.20 cm3 g-1. By immobilizing copper ions onto the mesopore walls, the standard peptide Angiotensin II could be identified in an extremely low concentration of 0.1 fmol µl-1 and in a mass ratio of 1:500 (Angiotensin II:BSA, m/m), which indicated significant sensitivity and a great size-exclusive ability. In addition, the introduction of polydopamine (PDA) made Fe3O4@mSiO2-Cu2+ more hydrophilic and biocompatible which could improve the profiling of endogenous peptides in bio-sample. Finally, 131 endogenous peptides were identified in human saliva after enrichment with Fe3O4@mSiO2-Cu2+. Therefore, Fe3O4@mSiO2-Cu2+ nanoparticles provided a promising candidate protocol for biomarker discovery.

3.
J Cell Physiol ; 235(2): 1013-1024, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31240715

RESUMO

Iron is an essential metal ion in the human body and usually dysregulated in cancers. However, a comprehensive overview of the iron-related genes and their clinical relevance in cancer is lacking. In this study, we utilized the expression profiling, proteomics, and epigenetics from the Cancer Genome Atlas database to systematically characterized the alterations of iron-related genes. There were multiple iron-related genes with dysregulation across 14 cancers and some of these ectopic changes may be associated with aberrant DNA methylation. Meanwhile, a variety of genes were significantly associated with patient survival, especially in kidney renal clear cell carcinoma. Then differentially expressed genes were validated in clinical samples. Finally, we found deferoxamine and erastin could inhibit proliferation in various tumor cells and influence the expression of several iron-related genes. Overall, our study provides a comprehensive analysis of iron metabolism across cancers and highlights the potential treatment of iron targeted therapies for cancers.

4.
J Cell Biochem ; 121(1): 723-734, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31452248

RESUMO

With the extensive use of dexmedetomidine (Dex) in the surgical resection of tumours for its potent sedative and analgesic properties, its effects on various properties of tumours have received increased attention. The study described herein aimed to investigate the effects of Dex on glioma cells in the presence or absence of cisplatin (DDP). Glioma U251 and U87MG cells were treated with different doses (1-50 nM) of Dex for 12 hours, then recultured in a Dex-free medium. In addition, Dex was added to U251 and U87MG cells 12 hours before or simultaneously with a 12-hour DDP treatment. Treatment with Dex increased the viability of both cell lines; this effect continued for at least 24 hours after Dex was removed. A cell invasion assay indicated that Dex inhibited cell invasion at 50 nM, but not at 10 nM. Western blot analysis showed that Dex increased the expression of phosphorylated extracellular-signal-regulated kinase 1/2, phosphoitide 3-kinase and p-AKT, but decreased ROCK protein levels at a dose of 50 nM. Intracellular Ca 2+ concentration was decreased by Dex in a dose-dependent manner. DDP toxicity was attenuated by 10 nM Dex added either before or with DDP treatment. However, pretreatment with 50 nM Dex instead enhanced the toxicity of DDP. Single-dose treatment with Dex did not significantly change glioma volume in nude mice, but changed the expression of Ki67 and matrix metalloproteinase-3 in the tumour. In conclusion, this study provides evidence of the regulatory effects of Dex on proliferation, invasion and chemosensitivity of glioma cells, and outlines potential mechanisms for these effects.

5.
Neurosci Lett ; 714: 134536, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31589904

RESUMO

Spiral ganglion neurons (SGNs) are primary afferent auditory neurons activated by inner hair cells in mammalian cochlea. Here, for the convenience of SGN studies such as patch-clamp or single cell RNA-sequence studies, a knock-in mouse (ShhCreEGFP/+; Rosa26-Tdtomatoloxp/+) was generated for the purpose of obtaining fluorescence SGNs. Auditory brainstem response (ABR) and Tuj1 immunohistochemistry staining were performed to verify the hearing function and the morphological characteristics. The results showed that there was no significant difference between shh and wild type mice. In electrophysiological studies, we verified a series of electrophysiological characteristics including the amplitude of sodium and potassium currents and action potential characteristics of shh and wild type mice and no significant differences were found either. From the above, shh mice have the same cell function and morphology as their littermate control wild type mice and could be used as an ideal tool to study the function and characteristics of spiral ganglion neurons. Potassium channels of SGNs play an important role in resolving time accuracy. We obtained similar amplitude of IK+ in neonatal and mature mice in the aging competition experiment, however, the density of IK+ from mature mice were significantly different from those of neonatal mice, a phenomenon that may play a key role in the nervous system. Potassium channels have been shown to contribute to apoptosis induced by cisplatin administration in various cell lines. Here we used cisplatin administration to study the ototoxicity and found that the effects of a low dose of cisplatin (0.5 mM correspond to therapeutic doses) causes a decrease in currents and is reversible after a short administration time. Moreover, we propose the activated state of potassium channels has changed but the characteristic and number remain still after cisplatin administration. The excess potassium ions may accumulate in the cell body, which had affected the firing properties and induce cytotoxicity and apoptosis. We suggest that the electrophysiological properties of acutely isolated SGNs may support further research on the mechanics of auditory propagation and ion channel pharmacology.

6.
Methods Mol Biol ; 2079: 155-166, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31728969

RESUMO

Cloning the open reading frame (ORF) of a protein-coding chimeric RNA into a mammalian expression vector is a simple, practiced way to study the function of the chimeric RNA. Here, we provide procedures for the insertion of the RRM2-C2orf48 fusion ORF into a mammalian expression vector, achieving the overexpression of the RRM2-C2orf48 fusion protein in a colon cancer cell line by retroviral transduction.

7.
Molecules ; 24(23)2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31783502

RESUMO

Hawthorn seed can be used to produce various bioactive compounds through destructive distillation. In this study, an accurate and feasible analytical method based on a gas chromatography mass spectrometer (GC-MS) was developed for simultaneous determination of six major compounds (contributing to more than 3% in total peak area) in destructive distillation extracts of hawthorn seed collected at different temperatures ranging from 150 to 270 °C. Then, a broth microdilution method coupled with grey correlation analysis was engaged in the evaluation of their antimicrobial activities and the screening of primarily active compounds. Results indicate that the extract collected from 211 to 230 °C had the highest content of six major compounds (furfural, 2-methoxyphenol, 2-methoxy-4-methylphenol, 4-ethyl-2-methoxyphenol, 2,6-dimethoxyphenol, and 5-tertbutylpyrogallol) and the strongest antibacterial activity. Besides, 2,6-dimethoxyphenol was found to be a potential compound in inhibiting the growth of vaginitis pathogens. This study provided an optimum temperature for the destructive distillation of hawthorn seed, reducing the waste of energy, and saving the cost of production in the hawthorn industry.

8.
Environ Pollut ; : 113631, 2019 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-31784271

RESUMO

Severe ozone (O3) pollution in China has magnified global concerns over the past years. Exploring the synoptic impacts and quantifying the source contributions are important for mitigating O3 pollution. This study focuses on the summertime O3 pollution over the Yangtze River Delta (YRD) in eastern China. We identify six predominant synoptic weather patterns (SWPs) over the YRD during 2013-2017 using the self-organising map (SOM) approach. We conduct O3 source attribution based on ozone source apportionment technology (OSAT) in a regional transport model. Surface O3 pollution is found to be sensitive to the predominant SWPs, including four O3-polluted types (northeasterly, northerly and southwesterly and anticyclone) and two O3-clean types (cyclone and the Meiyu front). The integrated influences of local chemistry and regional transport are important in O3 pollution under different SWPs. Daily maximum 8-h average (MDA8) O3 holds strong negative and positive correlations with relative humidity and sunshine duration, respectively. Among the six SWPs, the concentration and exceedance of MDA8 O3 reach their maxima under the northerly type on a regional average. Higher O3 levels, particularly under the northerly and northeasterly types, are primarily related to regional transport on various spatial scales. Local production accounts for the largest proportion of O3 sources under the anticyclone type. Under the southwesterly type, favourable weather conditions superimposed on regional transport lead to severe O3 pollution in coastal cities. The impact of super-regional transport is most pronounced along the eastern coast under the cyclone type. Source category analysis shows that transportation and industrial emissions play a prime role in surface O3 formation. This study illustrates the imperative implementation of joint emission control over eastern China to reduce O3 pollution.

10.
Langmuir ; 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31794669

RESUMO

Operando X-Ray Photoelectron spectroscopy (o-XPS) has been used to record the binding energy shifts in C1s peak of a pristine poly-ethylene glycol (PEG) liquid drop in an electrowetting on dielectric (EWOD) geometry, and after exposing it to several high-voltage breakdown processes. This was achieved by recording XPS data while the samples were subjected to 10 V DC and AC (square-wave modulation) actuations to extract electrical information related with the liquid and its interface with the dielectric. Through analysis of the XPS data under AC actuation a critical frequency of 170 Hz is extracted for the pristine PEG, which is translated to a resistance value of 14 MOhm for the liquid and a capacitance value of 60 pF for the dielectric, by help of simulations using an equivalent circuit model, and also by XPS analyses of a mimicking device, under similar conditions. The same measurements yield an increased value of 23 MOhm for the resistance of the liquid after the breakdown, by assuming the capacitance of the dielectric stays constant. In addition, an asymmetry in polarity dependence is observed with respect to both the onset of the breakdown voltage, and also the leakage behavior of the deteriorated (PEG + dielectric) system, such that deviations are more pronounced at positive voltages. Both DC and AC behaviors of the post-breakdown system can also be simulated, but only by introducing an additional element, a diode or a polarity and magnitude dependent voltage source (VCVS), which might be attributed to negative charge accumulation at the interface. Measurements for a liquid mixture of PEG with 8 % ionic liquid, yields almost two orders of magnitude smaller resistance for the drop, due to the enhanced conductivity by the ions. Coupled with modelling, XPS measurements under DC and AC modulations enable probing unique electrochemical properties of liquid/solid interfaces.

11.
Environ Pollut ; : 113653, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31801670

RESUMO

In freshwater ecosystems with frequent cyanobacterial blooms, the cyanobacteria toxin pollution is becoming increasingly serious. Nodularin (NOD), which has strong biological toxicity, has emerged as a new pollutant and affects the normal growth, development and reproduction of aquatic organisms. However, little information is available regarding this toxin. In this study, a graphene oxide material modified by L-cysteine was synthesized and used to immobilize microcystin-LR (MC-LR)-degrading enzyme (MlrA) to form an immobilized enzyme nanocomposite, CysGO-MlrA. Free-MlrA was used as a control. The efficiency of NOD removal by CysGO-MlrA was investigated. Additionally, the effects of CysGO-MlrA and the NOD degradation product on zebrafish lymphocytes were detected to determine the biological toxicity of these two substances. The results showed the following: (1) There was no significant difference in the degradation efficiency of NOD between CysGO-MlrA and free-MlrA; the degradation rate of both was greater than 80% at 1 h (2) The degradation efficiency of the enzyme could retain greater than 81% of the initial degradation efficiency after the CysGO-MlrA had been reused 7 times. (3) CysGO-MlrA retained greater than 50% of its activity on the 8th day when preserved at 0 °C, while free-MlrA lost 50% of its activity on the 4th day. (4) CysGO-MlrA and the degradation product of NOD showed no obvious cytotoxicity to zebrafish lymphocytes. Therefore, CysGO-MlrA might be used as an efficient and ecologically safe degradation material for NOD.

12.
Science ; 366(6467): 838-843, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31672915

RESUMO

The RSC complex remodels chromatin structure and regulates gene transcription. We used cryo-electron microscopy to determine the structure of yeast RSC bound to the nucleosome. RSC is delineated into the adenosine triphosphatase motor, the actin-related protein module, and the substrate recruitment module (SRM). RSC binds the nucleosome mainly through the motor, with the auxiliary subunit Sfh1 engaging the H2A-H2B acidic patch to enable nucleosome ejection. SRM is organized into three substrate-binding lobes poised to bind their respective nucleosomal epitopes. The relative orientations of the SRM and the motor on the nucleosome explain the directionality of DNA translocation and promoter nucleosome repositioning by RSC. Our findings shed light on RSC assembly and functionality, and they provide a framework to understand the mammalian homologs BAF/PBAF and the Sfh1 ortholog INI1/BAF47, which are frequently mutated in cancers.

13.
Artigo em Inglês | MEDLINE | ID: mdl-31677400

RESUMO

Water temperature can affect the metabolism of fish. Common carp (Cyprinus carpio) is a representative eurythermic fish that can survive at a wide range of ambient temperatures, allowing it to live in an extensive geographical range. The goal of this work was to study the glucose metabolism of common carp at different temperatures and determine the miRNAs involved in the regulation of glucose metabolism. We determined the indicators related to glucose metabolism after long-term temperature stress and constructed nine small RNA libraries of livers under different temperature stress (5 °C, 17 °C, and 30 °C, with three biological replicates for each temperature), and subjected these samples to high-throughput sequencing. A positive relationship was observed between weight gain rate (WGR) and temperature increase after 18 days of temperature stress. However, the glucose level in the plasma maintained a gentle decrease. Unexpectedly, liver lactic acid levels were elevated in HTG (high temperature group) and LTG (low temperature group). Six down-regulated miRNAs (miR-122, miR-30b, miR-15b-5p, miR-20a-5p, miR-1, and miR-7b) were identified as involved in the regulation of glycolysis. Twelve genes were predicted as targets of these miRNAs, and these genes are in pathways related to pyruvate metabolism, glycolysis/gluconeogenesis, and the citrate cycle (TCA cycle). The results allowed prediction of a potential regulatory network of miRNAs involved in the regulation of glycolysis. The target genes of six down-regulated miRNAs were up-regulated under temperature stress, including Aldolase C, fructose-bisphosphate, b (ALDOCB), multiple inositol-polyphosphate phosphatase 1 (MINPP1), phosphoenolpyruvate carboxykinase 1 (PCK1), pyruvate dehydrogenase E1 alpha 1 (PDHA1), aldehyde dehydrogenase 9 family member A1a (ALDH9A1A), Acetyl-coenzyme A synthetase (ACSS), lactate dehydrogenase b (LDH-b), and glyoxylate reductase/hydroxypyruvate reductase (GRHPR). Other key genes of glycolysis, glucose transporter 1 (GLUT-1), pyruvate kinase PKM (PKM), and mitochondrial pyruvate carrier (MPC) were significantly up-regulated in LTG and HTG. Overall, the results suggest that miRNAs maintain their energy requirements by regulating glycolysis and play an important role in the molecular response to cold and heat stress of common carp. These data provide the foundation for further studies of the role of miRNAs in environmental adaptation in fish.

14.
Sci Rep ; 9(1): 16356, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31705061

RESUMO

FeCrNiCu based high entropy alloy matrix composites were fabricated with addition of Si and C by vacuum electromagnetic induction melting. The primary goal of this research was to analyze the reaction mechanism, microstructure, mechanical properties at room temperature and strengthening mechanism of the composites with addition of Si and C. The reaction mechanism of powders containing (Si, Ni and C) was analyzed, only one reaction occurred (i.e., Si + C → SiC) and its activation energy is 1302.8 kJ/mol. The new composites consist of a face centered cubic (FCC) structured matrix reinforced by submicron sized SiC particles. The addition of Si and C enhances the hardness from 351.4 HV to 626.4 HV and the tensile strength from 565.5 MPa to 846.0 MPa, accompanied by a slight decrease in the plasticity. The main strengthening mechanisms of SiC/FeCrNiCu composites were discussed based on dislocation strengthening, load bearing effect, Orowan mechanism and solid solution hardening, whose contributions to the tensile strength increase are 58.6%, 6.3%, 14.3% and 20.8%, respectively.

15.
Cancer Lett ; 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31705928

RESUMO

Cervical cancer remains the first leading cause of cancer-related mortality among female reproductive system malignancies worldwide, and invasion and lymph node metastasis of cervical cancer represent the major reason for its poor prognosis. In this study, we found that RACK1 facilitated tumor cell invasion and lymphatic tube formation in vitro, as well as promoted lymphangiogenesis and lymph node metastasis in vivo in a galectin-1-dependent manner. Mechanism studies revealed that RACK1 promoted the expression and secretion of galectin-1 by reducing miR-1275 levels. Additionally, RACK1 also augmented galectin-1-induced downstream MEK/ERK, FAK, and AKT signaling via integrin-ß1 in cervical cancer cells. Tissue microarray confirmed that RACK1 was upregulated in squamous intraepithelial lesion and cancer, and RACK1 was positively correlated with invasion/metastasis phenotype, galectin-1 expression, and unfavorable prognosis in cervical cancer cases. Human papillomavirus E6 oncogene contributes to increased expression of RACK1 via the enhancement of its O-GlcNAcylation and protein stability. Together, our results demonstrate that RACK1 stimulates tumor invasion and lymph node metastasis of cervical cancer via galectin-1 and imply that targeting RACK1/galectin-1 axis provides promising means for cervical cancer treatment.

16.
Adv Mater ; : e1904283, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31693243

RESUMO

Compared with the quick development of polymer solar cells, achieving high-efficiency small-molecule solar cells (SMSCs) remains highly challenging, as they are limited by the lack of matched materials and morphology control to a great extent. Herein, two small molecules, BSFTR and Y6, which possess broad as well as matched absorption and energy levels, are applied in SMSCs. Morphology optimization with sequential solvent vapor and thermal annealing makes their blend films show proper crystallinity, balanced and high mobilities, and favorable phase separation, which is conducive for exciton dissociation, charge transport, and extraction. These contribute to a remarkable power conversion efficiency up to 13.69% with an open-circuit voltage of 0.85 V, a high short-circuit current of 23.16 mA cm-2 and a fill factor of 69.66%, which is the highest value among binary SMSCs ever reported. This result indicates that a combination of materials with matched photoelectric properties and subtle morphology control is the inevitable route to high-performance SMSCs.

17.
Xenotransplantation ; : e12568, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31693254

RESUMO

BACKGROUND: The design and fabrication of porous scaffolds are important issues for tissue engineering applications. In this study, we attempted to fabricate porous scaffolds using bovine pericardium (BP) and examined whether these scaffolds were beneficial for cell ingrowth and bioactive factors delivery. METHODS: A vacuum-freeze-thawing-Triton X-100 (VFTT) protocol was used to fabricate porous BP scaffolds. The porous and mechanical properties were assessed using histology, scanning electron microscopy, and mechanical assay. The fabricated scaffolds were seeded with mesenchymal stem cells (MSCs), and cell ingrowth was evaluated. Basic fibroblast growth factor (bFGF) was subsequently incorporated into the fabricated scaffolds. The bioactive factor delivery capacity was evaluated using loading and release studies. The bioactivity of released bFGF was assessed using a rat subcutaneous model. RESULTS: The BP scaffolds fabricated by the VFTT protocol displayed interconnected porous structures with porosity of 6.82 ± 1.36%.There were no significant differences in thickness, ultimate load, Young's modulus, and ultimate tensile strength between the fabricated porous BP scaffolds and native BPs (all P > .05). However, the water content of BPs was slightly reduced after VFTT treatment (P < .05). Cell ingrowth analysis showed that the seeded MSCs penetrated into the porous BP scaffolds with time of culture, while MSCs were limited to the surface layers of native BPs. Furthermore, bFGF was observed to be effectively loaded onto and released from the porous BP scaffolds. The released bFGF increased the phosphorylation levels of Akt, ERK 1/2, and MEK1/2, promoted host MSC recruitment, and inhibited myofibroblast differentiation in vivo. CONCLUSIONS: The porous BP scaffolds fabricated using a VFTT protocol were promising natural scaffolds for tissue engineering applications, since they had considerable mechanical properties as native BPs, supplied porous channels for cell ingrowth, and possessed bioactive factors delivery capability.

18.
Diabetes ; 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31712319

RESUMO

The whitening and loss of brown adipose tissue (BAT) during obesity and aging promote metabolic disorders and related diseases. The imbalance of Ca2+ homeostasis accounts for the dysfunction and clearance of mitochondria during BAT whitening. Capsaicin, a dietary factor activating TRPV1, can inhibit obesity induced by high-fat diet (HFD), but whether capsaicin inhibits BAT loss and the underlying mechanism remain unclear. In this study, we determined that the inhibitory effects capsaicin on HFD-induced obesity and BAT whitening were dependent on the participation of SIRT3, a critical mitochondrial deacetylase. SIRT3 also mediated all the beneficial effects of capsaicin on alleviating ROS generation, elevating mitochondrial activity and restricting mitochondrial calcium overload induced by HFD. Mechanistically, SIRT3 inhibits mitochondrial calcium uniporter (MCU)-mediated mitochondrial calcium overload by reducing the H3K27ac level on MCU promoter in an AMPK-dependent manner. In addition, HFD also inhibits AMPK activity to reduce SIRT3 expression, which could be reversed by capsaicin. Capsaicin intervention also inhibited aging-induced BAT whitening through this mechanism. In conclusion, this study emphasizes a critical role of AMPK/SIRT3 pathway in the maintenance of BAT morphology and function, and suggests that intervention in this pathway may be an effective target for preventing obesity or age-related metabolic diseases.

19.
Cell Prolif ; : e12725, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31746058

RESUMO

OBJECTIVES: Activation of the sympathetic system and adrenergic ß-receptors following traumatic bone defects negatively impairs bone regeneration. Whether preventing ß-receptor activation could potentially improve bone defect repair is unknown. In this study, we investigated the effect of systematic administration and local delivery of propranolol through composite scaffolds on bone healing. MATERIALS AND METHODS: Collagen/PVA/propranolol/hydroxyapatite(CPPH)composite scaffolds were fabricated with 3D printing technique and characterized by scanning electron microscope (SEM). Micro-CT analysis and bone formation histology were performed to detect new bone formation. Osteogenic differentiation of bone marrow stromal cells (BMSCs) and osteoclastogenesis of bone marrow monocytes cultured with scaffolds extract were performed for further verification. RESULTS: Intraperitoneal injection of propranolol did not significantly improve bone repair, as indicated by micro-CT analysis and bone formation histology. However, CPPH scaffolds exhibited sustained release of propranolol in vitro and significantly enhanced bone regeneration compared with vehicle collagen/PVA/hydroxyapatite (CPH) scaffolds in vivo. Moreover, in vitro experiments indicated the scaffolds containing propranolol promoted the osteogenic differentiation and migration of rat BMSCs and inhibited osteoclastogenesis by preventing ß-receptor activation. CONCLUSIONS: This study demonstrates that local adrenergic ß-receptor blockade can effectively enhance the treatment of bone defects by stimulating osteogenic differentiation, inhibiting osteoclastogenesis and enhancing BMSCs migration.

20.
Brain Res ; : 146511, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31672472

RESUMO

Isoflurane anesthesia is reported to induce insulin resistance (IR) in the peripheral tissues. However, researches on the impact of isoflurane on insulin-related metabolism in the central nervous system, especially in type 2 diabetes mellitus (T2DM), are scarce. This study sought to explore whether isoflurane anesthesia had a negative effect on insulin sensitivity both in peripheral and central tissues. Moreover, the possible role of isoflurane anesthesia in T2DM mice with pre-existing IR was analyzed. T2DM model in C57BL/6J mice was established by high fat diet (HFD) and single intraperitoneal injection of streptozotocin (STZ, 60 mg/kg). Both HFD/STZ-induced T2DM mice and normal mice received 6 h isoflurane exposure. Blood glucose level and serum insulin concentration were detected and the homeostasis model assessment of IR (HOMA-IR) index was calculated to estimate peripheral IR. Relative levels of genes and proteins in the insulin-dependent signaling pathway in mouse prefrontal cortex and hippocampus were determined to measure central IR. Results indicated that 6 h isoflurane exposure induced hyperglycemia, hyperinsulinemia and raised HOMA-IR index. Meanwhile, phosphorylated insulin receptor substrate-1 (pIRS1) (Ser639) and phosphorylated insulin receptor substrate-2 (pIRS2) (Ser731) were upregulated, while phosphorylated protein kinase B (pAKT) (Ser473) and phosphorylated glycogen synthase kinase-3 beta (pGSK3ß) (Ser9) were downregulated in the prefrontal cortex and hippocampus of anesthetized mice. Notably, isoflurane anesthesia significantly aggravated the degree of central IR in the aspects of gene transcriptions and protein expressions in HFD/STZ-induced T2DM mice with pre-existing IR. This study suggested that isoflurane anesthesia induced peripheral and central IR and aggravated pre-existing insulin resistance in T2DM mice.

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