Inhibition of α-glucosidase by 2-thiobarbituric acid: Molecular dynamics simulation integrating parabolic noncompetitive inhibition kinetics

Qin, Xiu-Yuan,Lee, Jinhyuk,Zheng, Li,Yang, Jun-Mo,Gong, Yan,Park, Yong-Doo Elsevier 2018 Process biochemistry Vol.65 No.-

<P><B>Abstract</B></P> <P>The phenomenon of α-glucosidase inhibition has attracted the attention of researchers due to its association with type 2 diabetes treatment in humans. In this study, we found that 2-thiobarbituric acid (TBA) induces complex inhibition of α-glucosidase using kinetics tests and molecular dynamics (MD) simulations. Computational MD and docking simulations demonstrate that TBA interacts with three residues on active sites of α-glucosidase such as Met69, Arg212, and His348. These biochemical tests indicate that TBA reversibly inhibits α-glucosidase in a parabolic noncompetitive manner (<I>IC</I> <SUB>50</SUB> =17.13±1.14mM; <I>K</I> <SUB>i</SUB> =13.25±0.56mM) and that this inhibition is accompanied by a biphasic kinetic process. The tertiary conformational changes were not synchronized with TBA inhibition but we observed hydrophobic disruption after inactivation at higher concentrations of TBA. Our results provide insight into the functional roles of residues located at the active sites of α-glucosidase, and we suggest that compounds similar to TBA (heterocyclic compounds) targeting the key residues of active sites are potential α-glucosidase inhibitors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> 2-Thiobarbituric acid (TBA) induces complex inhibition of α-glucosidase. </LI> <LI> Computational MD simulations demonstrate that TBA interacts with Met69, Arg212, and His348. </LI> <LI> TBA reversibly inhibits α-glucosidase in a parabolic noncompetitive manner (<I>IC</I> <SUB>50</SUB> =17.13±1.14mM; <I>K</I> <SUB>i</SUB> =13.25±0.56mM). </LI> <LI> The high dose of TBA induces hydrophobic disruption after inactivation. </LI> <LI> Heterocyclic compounds targeting the key residues of active sites are potential α-glucosidase inhibitors. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Effect of Glutamate on the Vestibulo-Solitary Projection after Sodium Nitroprusside-Induced Hypotension in Conscious Rats

Li, Li-Wei,Ji, Guang-Shi,Yang, Yan-Zhao,Ameer, Abdul Nasir,Kim, Min Sun,Park, Byung Rim,Jin, Yuan-Zhe The Korean Society of Pharmacology 2015 The Korean Journal of Physiology & Pharmacology Vol.19 No.3

Orthostatic hypotension is most common in elderly people, and its prevalence increases with age. Attenuation of the vestibulo-sympathetic reflex (VSR) is commonly associated with orthostatic hypotension. In this study, we investigated the role of glutamate on the vestibulo-solitary projection of the VSR pathway to clarify the pathophysiology of orthostatic hypotension. Blood pressure and expression of both pERK and c-Fos protein were evaluated in the nucleus tractus solitarius (NTS) after microinjection of glutamate into the medial vestibular nucleus (MVN) in conscious rats with sodium nitroprusside (SNP)-induced hypotension that received baroreceptor unloading via sinoaortic denervation (SAD). SNP-induced hypotension increased the expression of both pERK and c-Fos protein in the NTS, which was abolished by pretreatment with glutamate receptor antagonists (MK801 or CNQX) in the MVN. Microinjection of glutamate receptor agonists (NMDA or AMPA) into the MVN increased the expression of both pERK and c-Fos protein in the NTS without causing changes in blood pressure. These results indicate that both NMDA and AMPA receptors play a significant role in the vestibulo-solitary projection of the VSR pathway for maintaining blood pressure, and that glutamatergic transmission in this projection might play a key role in the pathophysiology of orthostatic hypotension.

Effectiveness of craniotomy and long- term survival in 35 patients with gestational trophoblastic neoplasia with brain metastases: a clinical retrospective analysis

Yuan Li,Weidi Wang,Xirun Wan,Fengzhi Feng,Yong-Lan He,Junjun Yang,Yang Xiang 대한부인종양학회 2022 Journal of Gynecologic Oncology Vol.33 No.3

Objective: To investigate the clinical characteristics, treatments, and prognostic factors among patients with gestational trophoblastic neoplasia (GTN) exhibiting brain metastases who underwent craniotomy. Methods: Thirty-five patients with GTN who had brain metastases and subsequently underwent craniotomies between January 1990 and December 2018 at Peking Union Medical College Hospital were identified using the GTN database. Their clinical manifestations, treatments, outcomes, and prognostic factors were retrospectively analyzed. Results: All 35 patients underwent decompressive craniotomy, hematoma removal, and metastatic tumor resection combined with multiagent chemotherapy. Eighty percent (28/35) achieved complete remission, 11.4% (4/35) achieved partial remission, and 8.6% (3/35) had progressive disease. Not counting 2 patients who were lost to follow-up, 81.8% of the patients (27/33) were alive after a median follow-up of 72 months. The 5-year overall survival rate was 80.4%. Univariate analysis revealed that a history of chemotherapy failure (p=0.020) and a >1-week interval between craniotomy and chemotherapy commencement (p=0.027) were adverse risk factors for survival. Multivariate analysis showed that previous chemotherapy failure remained an independent risk factor for poor survival (odds ratio=11.50; 95% confidence interval=1.55–85.15; p=0.017). Conclusion: Decompressive craniotomy is a life-saving option if metastatic hemorrhage and intracranial hypertension produce a risk of cerebral hernia in patients with GTN who have brain metastases. Higher survival rates and improved prognoses can be achieved through perioperative multidisciplinary cooperation and timely standard postoperative chemotherapy.

Liposome-mediated Induction of Apoptosis of Human Hepatoma Cells by C-Myc Antisense Phosphorothioate Oligodeoxynucleotide and 5-Fluorouracil

Yuan, Yuan,Cai, Hui,Yang, Xiao-Jun,Li, Wei,He, Jin,Guo, Tian-Kang,Chen, Yi-Rong Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.14

Background: The aim of this study was to investigate the effect of a c-myc antisense oligodeoxynucleotide and 5-fluorouracil on the expression of c-myc, invasion and proliferation of HEPG-2 liver cancer cells. Materials and Methods: HEPG-2 cells were treated with lipiosome-mediated c-myc ADSON and 5-fluorouracil. The proliferation inhibition rate and invasion were measured by MTT and invasion assay, respectively. Cell apoptosis was detected by flow cytometry and expression of c-myc by RT-PCR and immunohistochemistry. Results: The proliferation inhibition rate was significantly higher in the antisense oligodeoxynucleotide added-5-fluorouracil group than single antisense oligodeoxynucleotide or 5-fluorouracil group (p<0.05). G0/G1 cells in the antisense oligodeoxynucleotide group and S cells in the 5-fluorouracil groups were significantly increased than that in the control group, respectively (P<0.01). The amplification strips of PCR products in 5-FU, ASODN and combination groups were significantly weaker than that in the control group (P<0.01). The percentage of c-myc-protein-positive cells were significantly lower in antisense oligodeoxynucleotide, 5-fluorouracil and combination groups than that in the control group (P<0.01). Conclusions: A liposome-mediated c-myc antisense oligodeoxynucleotide and 5-fluorouracil can inhibit the proliferation and invasion of liver cancer cells by reducing the expression of c-myc. A c-myc antisense oligodeoxynucleotide can increase the sensitivity of liver cancer cells to 5-fluorouracil and decrease the dosage of the agent necessary for efficacy, providing an experimental basis for the clinical therapy of liver cancer.

Thermal phase transformation of In₂Se₃ nanowires studied by <i>in situ</i> synchrotron radiation X-ray diffraction

Li, Yang,Gao, Jing,Li, Qinliang,Peng, Mingfa,Sun, Xuhui,Li, Youyong,Yuan, Gang,Wen, Wen,Meyyappan, M. Royal Society of Chemistry 2011 Journal of materials chemistry Vol.21 No.19

<P>We report the preparation of α- and κ-phase In<SUB>2</SUB>Se<SUB>3</SUB> nanowires by thermal evaporation and investigation of their phase transformations <I>in situ</I> by synchrotron radiation X-ray diffraction (XRD) during a thermal annealing process. The κ-phase transformed into the α-phase at 500 °C and eventually transformed to high temperature α-phase with a layered structure of 5 atoms-5 atoms at 700 °C irreversibly. Different atomistic structures of In<SUB>2</SUB>Se<SUB>3</SUB> were modeled and optimized by DFT, which correlate well with the XRD results. The In<SUB>2</SUB>Se<SUB>3</SUB> nanowires also exhibit a large difference in resistivity before and after annealing.</P> <P>Graphic Abstract</P><P>In<SUB>2</SUB>Se<SUB>3</SUB> nanowires are synthesised by thermal evaporation and their phase transformations are investigated <I>in situ</I> by synchrotron radiation XRD. The nanowires also exhibit a large difference in resistivity before and after annealing. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1jm10419e'> </P>

Urinary Biomarkers for the Noninvasive Detection of Gastric Cancer

Li, Dehong,Yan, Li,Lin, Fugui,Yuan, Xiumei,Yang, Xingwen,Yang, Xiaoyan,Wei, Lianhua,Yang, Yang,Lu, Yan The Korean Gastric Cancer Association 2022 Journal of gastric cancer Vol.22 No.-

Gastric cancer (GC) is associated with high morbidity and mortality rates. Thus, early diagnosis is important to improve disease prognosis. Endoscopic assessment represents the most reliable imaging method for GC diagnosis; however, it is semi-invasive and costly and heavily depends on the skills of the endoscopist, which limit its clinical applicability. Therefore, the search for new sensitive biomarkers for the early detection of GC using noninvasive sampling collection methods has attracted much attention among scientists. Urine is considered an ideal biofluid, as it is readily accessible, less complex, and relatively stable than plasma and serum. Over the years, substantial progress has been made in screening for potential urinary biomarkers for GC. This review explores the possible applications and limitations of urinary biomarkers in GC detection and diagnosis.

An Interleaved Converter for 12-pulse Rectifier Harmonic Suppression

Li, Yuan,Yang, Wei,Cang, Sheng,Yang, Shiyan The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.5

In order to further improve the harmonic suppression capability of conventional 12-pulse rectifiers, this paper proposes a low harmonic 12-pulse rectifier using an Active Inter-Phase Reactor (AIPR). Through a detailed analysis of the relationship between the input current, output current and circulating current of the DC side, the mechanism where the AC grid side current harmonics can be suppressed by the DC side circulating current is revealed. On this basis, an interleaved APFC controlled by a DSP is designed and used as an AIPR along with an interphase reactor. A simulation is carried out with MATLAB/Simulink and an experiment is performed on a 9-kVA prototype. The obtained results verify the feasibility and validity of the proposed approach. Compared with a traditional 12-pulse rectifier, the THD can be reduced to 1/5 of the original value, and the capacity of the AIPR is only 2% of the load power. Thus, it is suitable for high-power applications.

Gut Microbiota Alteration Influences Colorectal Cancer Metastasis to the Liver by Remodeling the Liver Immune Microenvironment

Yuan Na,Li Xiaoyan,Wang Meng,Zhang Zhilin,Qiao Lu,Gao Yamei,Xu Xinjian,Zhi Jie,Li Yang,Li Zhongxin,Jia Yitao 거트앤리버 소화기연관학회협의회 2022 Gut and Liver Vol.16 No.4

Background/Aims:This study aimed to explore the effect of gut microbiota-regulated Kupffer cells (KCs) on colorectal cancer (CRC) liver metastasis. Methods: A series of in vivo and in vitro researches were showed to demonstrate the gut microbiota and its possible mechanism in CRC liver metastasis. Results: Fewer liver metastases were identified in the ampicillin-streptomycin-colistin and colistin groups. Increased proportions of Parabacteroides goldsteinii, Bacteroides vulgatus, Bacteroides thetaiotaomicron, and Bacteroides uniformis were observed in the colistin group. The significant expansion of KCs was identified in the ampicillin-streptomycin-colistin and colistin groups. B. vulgatus levels were positively correlated with KC levels. More liver metastases were observed in the vancomycin group. An increased abundance of Parabacteroides distasonis and Proteus mirabilis and an obvious reduction of KCs were noted in the vancomycin group. P. mirabilis levels were negatively related to KC levels. The number of liver metastatic nodules was increased in the P. mirabilis group and decreased in the B. vulgatus group. The number of KCs decreased in the P. mirabilis group and increased in the B. vulgatus group. In vitro, as P. mirabilis or B. vulgatus doses increased, there was an opposite effect on KC proliferation in dose- and time-dependent manners. P. mirabilis induced CT26 cell migration by controlling KC proliferation, whereas B. vulgatus prevented this migration. Conclusions: An increased abundance of P. mirabilis and decreased amount of B. vulgatus play key roles in CRC liver metastasis, which might be related to KC reductions in the liver.

EphB1 and Ephrin-B, New Potential Biomarkers for Squamous Cell/adenosquamous Carcinomas and Adenocarcinomas of the Gallbladder

Yuan, Yuan,Yang, Zhu-Lin,Miao, Xiong-Ying,Liu, Zi-Ru,Li, Dai-Qiang,Zou, Qiong,Li, Jing-He,Liang, Lu-Feng,Zeng, Gui-Xiang,Chen, Sen-Lin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.3

Squamous cell/adenosquamous carcinoma (SC/ASC) of the gallbladder are rare tumors and there are few clinical reports in the literature. Herein we report our clinical experience with 46 patients with SC/ASC and 80 with adenocarcinoma (AC). Expression of EphB1 and Ephrin-B in each tumor was determined using immunohistochemical methods for determination of correlations with prognosis. There was no difference in EphB1 and Ephrin-B expression between SC/ASC and AC tumors (P>0.05), but greater expression in those less than 3 cm in diameter, stage I or II (TNM stage), with no lymph node metastases, with no local invasion and treated with radical resection was apparent. Expression of EphB1 (P<0.05) and Ephrin-B (P<0.01) was higher in well differentiated than in poorly differentiated AC tumors. Kaplan-Meier survival analysis indicated that degree of differentiation, tumor diameter, lymph node metastases, local invasion, surgical approach and expression rate of EphB1 and Ephrin-B were closely related to the survival of SC/ASC (P<0.05) and AC patients (P<0.01). Patients with tumors that positive expressed EphB1 and Ephrin-B, whether it is SC/ASC ($P_{SC/ASC}$ =0.000) or AC ($P_{AC}$ =0.000 or $P_{AC}$ =0.002) had longer survival than those negative expression. Cox multivariate analysis indicated a negative correlation between expression of EphB1 or Ephrin-B and overall survival. Hence, EphB1 and Ephrin-B could be regarded as independent good prognostic factorsand important biological markers for SC/ASC and AC of gallbladder.

IL-6-6331 (T/C, rs10499563) is Associated with Decreased Risk of Gastric Cancer in Northern Chinese

Yang, Li,Sun, Ming-Jun,Liu, Jing-Wei,Xu, Qian,Yuan, Yuan Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Background: Polymorphisms of genes encoding cytokines could be potential biomarkers to predict risk of gastric cancer (GC). Here, we investigated the association between the IL-6 -6331 (T/C, rs10499563) polymorphism in its promoter region and GC risk. Methods: In this case-control study of 215 GC cases and 518 non-cancer controls, the IL-6 -6331 (T/C, rs10499563) polymorphism was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results: Individuals with the TC or CC genotype were associated with a significantly decreased risk of GC (OR=0.710, 95%CI: 0.504-0.999, P=0.049) compared with TT wild-type carriers. Ther C allele was also associated with significantly decreased risk of GC (OR=0.715, 95%CI: 0.536-0.954, P=0.023) compared with the T allele. In the stratification analysis, TC or CC genotypes were associated with significantly decreased GC risk in subgroups of males, people older than 60, and H. pylori-positive cases. However, no significant interaction was observed for TC or CC genotypes with H. pylori infection. On stratification with the Lauren classification, TC or CC genotypes were associated with significantly decreased risk of diffuse-type GC (OR=0.497, 95%CI: 0.266-0.925, P=0.027), also in subgroups of males, people older than 60, and H. pylori-positive cases. Conclusions: The IL-6 -6331 (T/C, rs10499563) polymorphism is associated with genetic susceptibility of GC and may have the potential to predict GC risk.