Pharmacological and electrophysiological characterization of rat P2X currents

Hai Ying Li,Seog Bae Oh,Joong Soo Kim The Korean Academy of Oral Biology 2008 International Journal of Oral Biology Vol.33 No.1

Adenosine 5’-triphosphate (ATP) is an important extracellular signaling molecule which is involved in a variety of physiological responses in many different tissues and cell types, by acting at P2 receptors, either ionotropic (P2X) or G protein-coupled metabotropic receptors (P2Y). P2X receptors have seven isoforms designated as P2X1-P2X7. In this study, we investigated the electrophysiological and pharmacological properties of rat P2X1-P2X4 currents by using whole-cell patch clamp technique in a heterologous expression system. When ATP-induced currents were analyzed in human embryonic kidney (HEK293) cells following transient transfection of rat P2X1-P2X4, the currents showed different pharmacological and electrophysiological properties. ATP evoked inward currents with fast activation and fast desensitization in P2X1- or P2X3- expressing HEK293 cells, but in P2X2- or P2X4-expressing HEK293 cells, ATP evoked inward currents with slow activation and slow desensitization. While PPADS and suramin inhibited P2X2 or P2X3 receptor-mediated currents, they had little effects on P2X4 receptor-mediated currents. Ivermectin potentiated and prolonged P2X4 receptor-mediated currents, but did not affect P2X2 or P2X3 receptor-mediated currents. We suggest that distinct pharmacological and electrophysiological properties among P2X receptor subtypes would be a useful tool to determine expression patterns of P2X receptors in the nervous system including trigeminal sensory neurons and microglia.

An Orbital Design Method for Satellite Formation Flying

Hai-Ying Cui,Jun-Feng Li,Yun-Feng Gao 대한기계학회 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.2

An orbital design method of the formation initialization based on the relative orbital element method is presented. It firstly constructed the relative motion equation of the satellite formation flying in terms of the leader and follower's orbital elements. Then the equation was simplified when the orbit eccentricity of the leader stellite was small. And according to the satellites' mission, a general design method for the relative trajectory was proposed. The advantage of this method is that one can get a very simple analytical formula of each follower satellite's orbital elements when the orbital eccentricity of the leader satellite is zero. The simulation results show that the method is effective.

Memory Enhancing and Neuroprotective Effects of Selected Ginsenosides

Hai Ying Bao,Jing Zhang,여수정,Chang-Seon Myung,Hyang Mi Kim,Jong Moon Kim,박정일,조정숙,Jong Seong Kang 대한약학회 2005 Archives of Pharmacal Research Vol.28 No.3

The effects of ginsenosides Rg3(R), Rg3(S) and Rg5/Rk1 (a mixture of Rg5 and Rk1, 1:1, w/w), which are components isolated from processed Panax ginseng C.A. Meyer (Araliaceae), on memory dysfunction were examined in mice using a passive avoidance test. The ginsenosides Rg3(R), Rg3(S) or Rg5/Rk1, when orally administered for 4 days, significantly ameliorated the memory impairment induced by the single oral administration of ethanol. The memory impairment induced by the intraperitoneal injection of scopolamine was also significantly recovered by ginsenosides Rg3(S) and Rg5/Rk1. Among the three ginsenosides tested in this study, Rg5/Rk1 enhanced the memory function of mice most effectively in both the ethanoland scopolamine-induced amnesia models. Moreover, the latency period of the Rg5/Rk1-treated mice was 1.2 times longer than that of the control (no amnesia) group in both models, implying that Rg5/Rk1 may also exert beneficial effects in the normal brain. We also evaluated the effects of these ginsenosides on the excitotoxic and oxidative stress-induced neuronal cell damage in primary cultured rat cortical cells. The excitotoxicity induced by glutamate or Nmethyl- D-aspartate (NMDA) was dramatically inhibited by the three ginsenosides. Rg3(S) and Rg5/Rk1 exhibited a more potent inhibition of excitotoxicity than did Rg3(R). In contrast, these ginsenosides were all ineffective against the H2O2- or xanthine/xanthine oxidase-induced oxidative neuronal damage. Taken together, these results indicate that ginsenosides Rg3(S) and Rg5/Rk1 significantly reversed the memory dysfunction induced by ethanol or scopolamine, and their neuroprotective actions against excitotoxicity may be attributed to their memory enhancing effects.

L-carnitine treatment attenuates renal tubulointerstitial fibrosis induced by unilateral ureteral obstruction

( Hai Yan Zhao ),( Hui Ying Li ),( Jian Jin ),( Ji Zhe Jin ),( Long Ye Zhang ),( Mei Ying Xuan ),( Xue Mei Jin ),( Yu Ji Jiang ),( Hai Lan Zheng ),( Ying Shun Jin ),( Yong Jie Jin ),( Bum Soon Choi ) 대한내과학회 2021 The Korean Journal of Internal Medicine Vol.36 No.0

Background/Aims: Accumulating evidence indicates that L-carnitine (LC) protects against multiorgan damage through its antioxidant properties and preservation of the mitochondria. Little information is available about the effects of LC on renal fibrosis. This study examined whether LC treatment would provide renoprotection in a rat model of unilateral ureteral obstruction (UUO) and in vitro. Methods: Sprague-Dawley rats that underwent UUO were treated daily with LC for 7 or 14 days. The influence of LC on renal injury caused by UUO was evaluated by histopathology, and analysis of gene expression, oxidative stress, mitochondrial function, programmed cell death, and phosphatidylinositol 3-kinase (PI3K)/ AKT/forkhead box protein O 1a (FoxO1a) signaling. In addition, H₂O₂-exposed human kidney cells (HK-2) were treated with LC. Results: LC treatment inhibited expression of proinflammatory and profibrotic cytokines, and was followed by a significant attenuation of tubulointerstitial inflammation and fibrosis. The increased oxidative stress caused by UUO was associated with mitochondrial dysfunction and excessive apoptosis and autophagy via PI3K/AKT/FoxO1a-dependent signaling, and this was abrogated by administration of LC. In H₂O₂-exposed HK-2 cells, LC decreased intracellular production of reactive oxygen species, and suppressed expression of profibrotic cytokines and reduced the number of apoptotic cells. Conclusions: LC protects against the progression of tubulointerstitial fibrosis in an obstructed kidney.

Web-Development ; A Comparison of Price and Price Dispersion of Online Retailers in Different Internet Maturity Stage

Hai Ying Li,Gee Woo Bock,Sang Yong Tom Lee 한국경영정보학회 2005 한국경영정보학회 학술대회논문집 Vol.2005 No.-

BAG5 regulates PTEN stability in MCF-7 cell line

( Ying Zhang ),( Hai Yan Gao ),( Hai Dong Gao ) 생화학분자생물학회(구 한국생화학분자생물학회) 2013 BMB Reports Vol.46 No.10

The phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a tumor-suppressing lipid phosphatase that is frequently absent in breast tumors. Thus, the stability of PTEN is essential for tumor prevention and therapy. The ubiquitinproteasome pathway has an important role in regulating the functions of PTEN. Specifically, carboxyl terminus Hsp70- interacting protein (CHIP), the E3 ubiquitin ligase of PTEN, can regulate PTEN levels. In this study, we report that BCL-2- associated athanogene 5 (BAG5), a known inhibitor of CHIP activity, reduces the degradation of PTEN and maintains its levels via an ubiquitylation-dependent pathway. BAG5 is identified as an antagonist of cell tumorigenicity. [BMB Reports 2013; 46(10): 490-494]

Identification and Characterization of Gonatobotryum apiculatum Causing Leaf Spot and Blight on Sinowilsonia henryi

( Ying Gao ),( Hai Feng Liu ),( Zheng Xing Song ),( Xiao Ying Du ),( Jian Xin Deng ) 한국균학회 2020 Mycobiology Vol.48 No.1

Sinowilsonia henryi is a rare and endangered plant, as well as an endemic species in China. In July 2018, leaf spot and blight disease was observed on S. henryi in Yichang, Hubei, China. A fungus isolated from disease tissues was identified as Gonatobotryum apiculatum based on morphology and sequence analyses of ITS and LSU regions. Phylogenetic analyses indicated that the species belongs to Dothioraceae (Dothideales). Morphologically, the species produced two distinct types of conidia from authentic media, both conidia were described here. Pathogenicity tests showed that the fungus is a pathogen causing leaf spots on S. henryi. This is the first report of leaf spot and blight disease on S. henryi caused by G. apiculatum in China.

Upregulation of PITX2 Promotes Letrozole Resistance Via Transcriptional Activation of IFITM1 Signaling in Breast Cancer Cells

Ying-ying Xu,Hai-ru Yu,Jia-yi Sun,Zhao Zhao,Shuang Li,Xin-feng Zhang,Zhi-xuan Liao,Ming-ke Cui,Juan Li,Chan Li,Qiang Zhang 대한암학회 2019 Cancer Research and Treatment Vol.51 No.2

Purpose Although the interferon  (IFN) signaling and the paired-like homeodomain transcription factor 2 (PITX2) have both been implicated in the progression of breast cancer (BCa), it remains obscure whether these two pathways act in a coordinated manner. We therefore aimed to elucidate the expression and function of PITX2 during the pathogenesis of endocrine resistance in BCa. Materials and Methods PITX2 expression was assessed in BCa tissues using quantitative reverse transcription polymerase chain reaction (RT-qPCR) and immunohistochemistry and in experimentally induced letrozole-resistant BCa cells using RT-qPCR and immunoblotting. Effects of PITX2 deregulation on BCa progression was determined by assessing MTT, apoptosis and xenograft model. Finally, using multiple assays, the transcriptional regulation of interferon-inducible transmembrane protein 1 (IFITM1) by PITX2 was studied at both molecular and functional levels. Results PITX2 expression was induced in letrozole-resistant BCa tissues and cells, and PITX2 induction by IFN signaling powerfully protected BCa cells against letrozole insult and potentiated letrozole-resistance. Mechanistically, PITX2 enhanced IFN-induced AKT activation by transactivating the transcription of IFITM1, thus rendering BCa cells unresponsive to letrozoleelicited cell death. Additionally, ablation of IFITM1 expression using siRNA substantially abolished IFN-elicited AKT phosphorylation, even in the presence of PITX2 overexpression, thus sensitizing BCa cells to letrozole treatment. Conclusion These results demonstrate that constitutive upregulation of PITX2/IFITM1 cascade is an intrinsic adaptive mechanism during the pathogenesis of letrozole-resistance, and modulation of PITX2/IFITM1 level using different genetic and pharmacological means would thus have a novel therapeutic potential against letrozole resistance in BCa.

Eugenol Inhibits ATP-induced P2X Currents in Trigeminal Ganglion Neurons

Hai Ying Li,Byung Ky Lee,Joong Soo Kim,Sung Jun Jung,Seog Bae Oh 대한생리학회-대한약리학회 2008 The Korean Journal of Physiology & Pharmacology Vol.12 No.6

Eugenol is widely used in dentistry to relieve pain. We have recently demonstrated voltage-gated Na⁺ and Ca²⁺ channels as molecular targets for its analgesic effects, and hypothesized that eugenol acts on P2X₃, another pain receptor expressed in trigeminal ganglion (TG), and tested the effects of eugenol by whole-cell patch clamp and Ca²⁺ imaging techniques. In the present study, we investigated whether eugenol would modulate 5 -triphosphate (ATP)-induced currents in rat TG neurons and P2X₃-expressing human embryonic kidney (HEK) 293 cells. ATP-induced currents in TG neurons exhibited electrophysiological properties similar to those in HEK293 cells, and both ATP- and Ձ,Ղ-meATP-induced currents in TG neurons were effectively blocked by TNP-ATP, suggesting that P2X₃ mediates the majority of ATP-induced currents in TG neurons. Eugenol inhibited ATP-induced currents in both capsaicin-sensitive and capsaicin-insensitive TG neurons with similar extent, and most ATP-responsive neurons were IB4-positive. Eugenol inhibited not only Ca²⁺ transients evoked by Ձ,Ղ-meATP, the selective P2X₃ agonist, in capsaicin-insensitive TG neurons, but also ATP-induced currents in P2X₃-expressing HEK293 cells without co-expression of transient receptor potential vanilloid 1 (TRPV1). We suggest, therefore, that eugenol inhibits P2X₃ currents in a TRPV1-independent manner, which contributes to its analgesic effect.

An Agricultural Land Contractual Management Transfer Prediction Model Based on Analytic Hierarchy Process and Logistic Regression

Hai-ying Cao,Ling Wu 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.10

In the field of application prediction, there are two kinds of common methods to establish the prediction model: prediction model established by artificial data analysis relying on expert experience, and prediction model achieved by statistical model exploiting data analysis. However, the prediction accuracy of the model based on expert is restricted by the experiences, while the model based on statistical analysis is limited by the quality and scale of the training data. In view of the advantages and disadvantages of these two kinds of models, this paper presents a prediction model by integrating Analytic Hierarchy Process and Logistic Regression. The proposed prediction model uses the Analytic Hierarchy Process, which are based on the training data and expert experience to obtain the rank of predominant factor in a specific domain, and exploits the logistical regression model to learn the weights of each influencing factor. Finally, the linear combination of the two models is used to obtain the prediction model. Further, we take agricultural land contractual management transfer prediction as an example to test the proposed hybrid prediction model.