Sitagliptin attenuates endothelial dysfunction independent of its blood glucose controlling effect

Xin-Miao Chang,Fei Xiao,Qi Pan,Xiao-Xia Wang,Li-Xin Guo 대한생리학회-대한약리학회 2021 The Korean Journal of Physiology & Pharmacology Vol.25 No.5

Although the contributions of sitagliptin to endothelial dysfunction in diabetes mellitus were previously reported, the mechanisms still undefined. Autophagy plays an important role in the development of diabetes mellitus, but its role in diabetic macrovascular complications is unclear. This study aims to observe the effect of sitagliptin on macrovascular endothelium in diabetes and explore the role of autophagy in this process. Diabetic rats were induced through administration of high-fat diet and intraperitoneal injection of streptozotocin. Then diabetic rats were treated with or without sitagliptin for 12 weeks. Endothelial damage and autophagy were measured. Human umbilical vein endothelial cells were cultured either in normal glucose or in high glucose medium and intervened with different concentrations of sitagliptin. Rapamycin was used to induce autophagy. Cell viability, apoptosis and autophagy were detected. The expressions of proteins in c-Jun N-terminal kinase (JNK)-Bcl-2-Beclin-1 pathway were measured. Sitagliptin attenuated injuries of endothelium in vivo and in vitro. The expression of microtubuleassociated protein 1 light chain 3 II (LC3II) and beclin-1 were increased in aortas of diabetic rats and cells cultured with high-glucose, while sitagliptin inhibited the over-expression of LC3II and beclin-1. In vitro pre-treatment with sitagliptin decreased rapamycin-induced autophagy. However, after pretreatment with rapamycin, the protective effect of sitagliptin on endothelial cells was abolished. Further studies revealed sitagliptin increased the expression of Bcl-2, while inhibited the expression of JNK in vivo. Sitagliptin attenuates injuries of vascular endothelial cells caused by high glucose through inhibiting over-activated autophagy. JNK-Bcl-2-Beclin-1 pathway may be involved in this process.

Highly synergic adsorption and photocatalytic degradation of walnut shell biochar/NiCr-layered double hydroxides composite for Methyl orange

Xiao-fang Li,Rui-xian Li,Ke-xin Wang,Xiao-qiang Feng 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.126 No.-

Methyl orange (MO) is a kind of azo dye, and will do great harm to the ecological environment. Alleviating this problem by removing MO is crucial role to prevent harmful damage to the environment. In this paper, NiCr layered double hydroxides (LDH) were prepared through hydrothermal method andthen modified with different mass rations of walnut shell biochar. The structure and properties ofbiochar/NiCr-LDH composites were analyzed by Fourier transform infrared spectroscopy (FT-IR), powderX-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) coupled with energy dispersespectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). Moreover, the adsorption andphotocatalytic degradation behavior of composites on anionic dye MO were investigated. Characterization results indicated that NiCr-LDH was perfectly synthesized and coated on the biochar. All the biochar/NiCr-LDH composites show enhanced adsorption and photodegradation performancefor MO dye compared with pure NiCr-LDH and biochar. When the biochar content was 22.3 wt.% andthe biochar/NiCr-LDH (S2) dosage was 1.0 mg/mL, the maximum removal amount of MO could reach100 % within 60 min at the natural pH, experimental data fitted well with the pseudo-second-orderkinetic and Freundlich isotherm model, and the maximum adsorption capacity of S2 was 108.2 mg/g. Besides, compared with NiCr-LDH, S2 also demonstrated wonderful photodegradation activity for MOunder visible-light irradiation, the rate constant of S2 (0.0173 min1) is about 1.5 times that of NiCr-LDH (0.0118 min1), and the enhanced performance can be due to the faster separation of electronholepairs, in which biochar acted as charge separation carriers. Meanwhile, the hydroxyl radical andsuperoxide radical played crucial roles in the dye photocatalytic degradation, and a possible photocatalyticdegradation mechanism was proposed. The excellent photocatalytic activity and stability makebiochar/NiCr-LDH an ideal photocatalyst to solve environmental crisis.

RNA silencing-mediated resistance is related to biotic/abiotic stresses and cellular RdRp expression in transgenic tobacco plants

( Xiao Liang Wu ),( Wen Cui Hou ),( Mei Mei Wang ),( Xiao Ping Zhu ),( Fang Li ),( Jie Dao Zhang ),( Xin Zheng Li ),( Xing Qi Guo ) 생화학분자생물학회 2008 BMB Reports Vol.41 No.5

A Danger Theory Inspired Protection Approach for Hierarchical Wireless Sensor Networks

( Xin Xiao ),( Ruirui Zhang ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.5

With the application of wireless sensor networks in the fields of ecological observation, defense military, architecture and urban management etc., the security problem is becoming more and more serious. Characteristics and constraint conditions of wireless sensor networks such as computing power, storage space and battery have brought huge challenges to protection research. Inspired by the danger theory in biological immune system, this paper proposes an intrusion detection model for wireless sensor networks. The model abstracts expressions of antigens and antibodies in wireless sensor networks, defines meanings and functions of danger signals and danger areas, and expounds the process of intrusion detection based on the danger theory. The model realizes the distributed deployment, and there is no need to arrange an instance at each sensor node. In addition, sensor nodes trigger danger signals according to their own environmental information, and do not need to communicate with other nodes, which saves resources. When danger is perceived, the model acquires the global knowledge through node cooperation, and can perform more accurate real-time intrusion detection. In this paper, the performance of the model is analyzed including complexity and efficiency, and experimental results show that the model has good detection performance and reduces energy consumption.

Cinnamaldehyde Derivatives Inhibit Coxsackievirus B3-Induced Viral Myocarditis

( Xiao-qiang Li ),( Xiao-xiao Liu ),( Xue-ying Wang ),( Yan-hua Xie ),( Qian Yang ),( Xin-xin Liu ),( Yuan-yuan Ding ),( Wei Cao ),( Si-wang Wang ) 한국응용약물학회 2017 Biomolecules & Therapeutics(구 응용약물학회지) Vol.25 No.3

The chemical property of cinnamaldehyde is unstable in vivo, although early experiments have shown its obvious therapeutic effects on viral myocarditis (VMC). To overcome this problem, we used cinnamaldehyde as a leading compound to synthesize derivatives. Five derivatives of cinnamaldehyde were synthesized: 4-methylcinnamaldehyde (1), 4-chlorocinnamaldehyde (2), 4-methoxycinnamaldehyde (3), α-bromo-4-methylcinnamaldehyde (4), and α-bromo-4-chlorocinnamaldehyde (5). Neonatal rat cardiomyocytes and HeLa cells infected by coxsackievirus B3 (CVB3) were used to evaluate their antiviral and cytotoxic effects. In vivo BALB/c mice were infected with CVB3 for establishing VMC models. Among the derivatives, compound 4 and 5 inhibited the CVB3 in HeLa cells with the half-maximal inhibitory concentrations values of 11.38 ± 2.22 μM and 2.12 ± 0.37 μM, respectively. The 50% toxic concentrations of compound 4 and 5-treated cells were 39-fold and 87-fold higher than in the cinnamaldehyde group. Compound 4 and 5 effectively reduced the viral titers and cardiac pathological changes in a dose-dependent manner. In addition, compound 4 and 5 significantly inhibited the secretion, mRNA and protein expressions of inflammatory cytokines TNF-α, IL-1β and IL-6 in CVB3-infected cardiomyocytes, indicating that brominated cinnamaldehyde not only improved the anti-vital activities for VMC, but also had potent anti-inflammatory effects in cardiomyocytes induced by CVB3.

Molecular cloning and characterization of two novel DREB genes encoding dehydration-responsive element binding proteins in halophyte Suaeda salsa

Xiao-Bo Sun,Hong-Xiang Ma,Xin-Ping Jia,Yu Chen,Xiao-Qing Ye 한국유전학회 2015 Genes & Genomics Vol.37 No.2

The dehydration-responsive element-binding(DREB) proteins play an important role in regulatingexpression of stress-inducible genes under abiotic stresses. In this study, two genes encoding putative DREB proteins,named SsDREBa and SsDREBb, were cloned from halophyteSuaeda salsa L. using RACE method. The deducedSsDREBa and SsDREBb proteins contain a typical AP2/ERF domain. Multiple sequence alignments and phylogeneticanalysis revealed that the two SsDREB genes of S. salsa were highly similar in AP2/ERF domains at thenucleotide and amino acid levels and belong to the A-6subgroup of the DREB transcription factor subfamily. Asubcellular localization assay showed that both SsDREBslocalized to the nucleus. Yeast one-hybrid experimentstestified that both proteins were able to specifically bind tothe DRE sequence and activate the expression of the downstreamHIS reporter gene in yeast. Quantitative real-timePCR analysis demonstrated that under normal conditions,the expression level of SsDREBa was the most high in theroots and no SsDREBa mRNAs were detected in the stems;SsDREBb expressed at relatively higher levels in the leavesthan in the roots and stems. The expression of SsDREa andSsDREBb genes in S. salsa roots and leaves was remarkablyinduced by high-salt and dehydration treatments, butnot by cold and ABA, and exhibited stronger induction inroots and leaves, respectively. These results indicate thatthe SsDREBa and SsDREBb are novel stress-responsivetranscription factors, which are involved in the drought andhigh-salt stress responses through ABA-independent pathwaysand could be used for production of stress-toleranttransgenic crops.

A novel method for the synthesis of nano-sized MgAl2O4 spinel ceramic powde

Xiao-ping Liang,Rong-tao Wang,Ying Peng,Xiao-wei Fan,Jian-xin Li 한양대학교 세라믹연구소 2010 Journal of Ceramic Processing Research Vol.11 No.2

This study describes the preparation and characterization of MgAl2O4 spinel ceramic powders by a polyacrylamide gel method with Al(NO3)3·9H2O and Mg(NO3)3·6H2O as the raw materials, acrylamide as the monomer, N,N-mehtylenebisacrylamide as the cross-linking agent, and deionized water as the solvent. The nanopowders were studied by X-ray diffraction (XRD) and a transmission electron microscope (TEM). The results showed that the nanopowders having a typical spinel structure are ultrapure and nano-sized. Due to the hindering effect of the polyacrylamide network, the average grain size of the MgAl2O4spinel is approximately 20 nm. Moreover, it is confirmed that the optimal sintering temperature for synthesizing the MgAl2O4spinel ceramic nanopowders is 900 oC, which is about 600-1000 oC lower than that of the traditional solid-state method.

Chk2 Regulates Cell Cycle Progression during Mouse Oocyte Maturation and Early Embryo Development

Xiao-Xin Dai,Xing Duan,Honglin Liu,최향순,Nam-Hyung Kim,Shao-Chen Sun 한국분자세포생물학회 2014 Molecules and cells Vol.37 No.2

As a tumor suppressor homologue during mitosis, Chk2 is involved in replication checkpoints, DNA repair, and cell cycle arrest, although its functions during mouse oocyte meiosis and early embryo development remain uncertain. We investigated the functions of Chk2 during mouse oocyte maturation and early embryo development. Chk2 exhibited a dynamic localization pattern; Chk2 expression was restricted to germinal vesicles at the germinal vesicle (GV) stage, was associated with centromeres at pro-meta-phase I (Pro-MI), and localized to spindle poles at meta-phase I (MI). Disrupting Chk2 activity resulted in cell cycle progression defects. First, inhibitor-treated oocytes were arrested at the GV stage and failed to undergo germinal vesicle breakdown (GVBD); this could be rescued after Chk2 inhibition release. Second, Chk2 inhibition after oocyte GVBD caused MI arrest. Third, the first cleavage of early embryo development was disrupted by Chk2 inhibi-tion. Additionally, in inhibitor-treated oocytes, checkpoint protein Bub3 expression was consistently localized at cen-tromeres at the MI stage, which indicated that the spindle assembly checkpoint (SAC) was activated. Moreover, disrupting Chk2 activity in oocytes caused severe chromo-some misalignments and spindle disruption. In inhibitor-treated oocytes, centrosome protein γ-tubulin and Polo-like kinase 1 (Plk1) were dissociated from spindle poles. These results indicated that Chk2 regulated cell cycle progression and spindle assembly during mouse oocyte maturation and early embryo development.

Isolation, Characterization, and Application of Chitosan-Degrading Fungus from Soil

( Xin Lin Wei ),( Wei Chen ),( Ming Xiao ),( Jian Bo Xiao ),( Yuan Feng Wang ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.7

Clinical Study on Fluvoxamine Combined with Oxycodone Prolonged-Release Tablets in Treating Patients with Moderate to Severe Cancer Pain

Xiao, Yang,Liu, Jun,Huang, Xin-En,Ca, Li-Hua,Ma, Yi-Min,Wei, Wei,Zhang, Rong-Xia,Huang, Xiao-Hong,Chang, Juan,Wu, Yi-Jia Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

Objective: To observe treatment effects and safety of fluvoxamine combined with oxycodone prolonged-release tablets in treating patients with moderate to severe cancer pain. Methods: Patients confirmed pathologically with cancer and complicated with moderate to severe pain, were divided into control and experimental groups. Oxycodone prolonged-release tablets, with or without fluvoxamine, were administrated to all study patients until pain relief. Degree of pain relief, dose of oxycodone prolonged-release tablets, side effects and quality of life were compared before and after treatment. Results: In total, 120 patients were recruited. No statistically significant difference was detected regarding age, gender, types of cancer, KPS between two groups of patients (P>0.05). Baseline pain score of patients with moderate pain in treatment and control group was $4.9{\pm}0.8$ and $5.1{\pm}0.8$, respectively; and decreased to $1.8{\pm}1.1$ and $1.2{\pm}1.1$ after treatment, respectively. Pain intensity was significantly reduced in the treatment group (P=0.028). Average daily consumption of oxycodone prolonged-release tablets was ($54.0{\pm}19.6$) mg and ($44.7{\pm}18.7$) mg respectively, which is lower in treatment grpup than in control group, but the difference was not statistically significant (P=0.065). Baseline pain score of patients with severe pain in treatment and control groups were $8.3{\pm}1.1$ and $8.3{\pm}1.1$, respectively; and pain intensity after treatment decreased to $2.9{\pm}1.0$ and $2.3{\pm}1.0$. Pain intensity was significantly reduced in the treatment group, with statistical significance (P=0.026). Average daily consumption of oxycodone prolonged-release tablets was ($132.0{\pm}42.2$) mg and ($110.7{\pm}33.9$) mg, respectively, which is lower in treatment group than in control group, and the difference was statistically significant (P=0.035). In terms of quality of life, patients in treatment group had better performance status, daily activity, mood, and sleep than that in control group (P < 0.05). Patients in two groups had similar side effects, eg., constipation, nausea/vomiting, lethargy, dizziness, itchy skin, dysuria, and ataxia. Lower incidence of nausea/vomiting, lethargy, was obtained from patients in treatment than in control group, while significant low constipation was observed in treatment than in control group (35.0% vs 49.2%, P=0.026). Conclusion: Fluvoxamine combined with oxycodone prolonged-release tablets could be more effective in treating patients with cancer pain, and could reduce the dosage of oxycodone prolonged-release tablets and thus be associated with lower side effects, and improved quality of life.