• Title/Summary/Keyword: P2X receptor

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Scorpion Venom Activates Both $Ca^{2+}-ATPase$ and Inositol 1,4,5-trisphosphate Receptor in the Microsomes of Tracheal Epithelial Cells (전갈독소에 의한 호흡기 상피세포 마이크로솜 $Ca^{2+}-ATPase$와 Inositol 1,4,5-trisphosphate 수용체의 활성촉진)

  • Cho, Kyong-Soo;Park, Kyoung-Sun;Kim, Young-Kee
    • Applied Biological Chemistry
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    • v.39 no.3
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    • pp.189-194
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    • 1996
  • The effects of scorpion (Leiurus quinquestriatus hebraeus, Lqh) venom were evaluated on the activities of microsomal $Ca^{2+}-ATPase$ and $Ca^{2+}$ release channel prepared from the epithelial cells of pig airway. Whole venom of Lqh $(120\;{\mu}g/ml)$ increased the activity of microsomal $Ca^{2+}-ATPase$ about 32% in the tight-sealed microsomes and about 28% in the Triton X-100-treated or $Ca^{2+}$ ionophore A23187-treated leaky microsomes. Thapsigargin, a specific antagonist of $Ca^{2+}-ATPase$, inhibited 42% of total ATPase activity and also completely blocked the effects of Lqh venom, suggesting that Lqh venom directly activiates the microsomal $Ca^{2+}-ATPase$. In order to determine if Lqh venom increases the microsomal uptake of $^{45}Ca^{2+}$, Lqh venom was added in the uptake medium. The Lqh venom increased microsomal $^{45}Ca^{2+}$ uptake up to ${\sim}20%$ and the increase was only observed when heparin, an antagonist of $InsP_3$ receptor channel, was added in the uptake medium. Lqh venom in the absence of heparin unexpectedly decreased the rate and the amount of $^{45}Ca^{2+}$ uptake. These results were explained by simultaneous increases in $^{45}Ca^{2+}$ release as well as $^{45}Ca^{2+}$ uptake by Lqh venom. Lqh venom itself increased the release of $^{45}Ca^{2+}$ as much as $^{45}Ca^{2+}$ release by $4\;{\mu}m\;InsP_3$, implying that Lqh venom also activates $InsP_3$ receptor, microsomal $Ca^{2+}$ release channel. Based on these results, we suggest that the Lqh venom consists of at least two components; one activates the $InsP_3$ receptor and the other avates the $Ca^{2+}-ATPase$. Currently we a investigating the chemical and electrophysiological properties of the active components of Lqh venom.

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Association between Melatonin Receptor 1A Gene and Expression of Reproductive Seasonality in Sheep

  • Chu, M.X.;Cheng, D.X.;Liu, W.Z.;Fang, L.;Ye, S.C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.8
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    • pp.1079-1084
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    • 2006
  • To determine whether a link exists between reproductive seasonality and the structure of the melatonin receptor 1A (MTNR1A) gene, the latter was studied in nonseasonal estrous breeds (Small Tail Han and Hu ewes) and seasonal estrous breeds (Dorset, Suffolk and German Mutton Merino ewes). A large fragment of the exon 2 of the MTNR1A gene was amplified and a uniform fragment of 824 bp was obtained in 239 ewes of five breeds. The 824 bp PCR product was digested with restriction endonucleases Mnl I and Rsa I, and checked for the presence of restriction sites. The presence (allele M) or absence (allele m) of an Mnl I site at base position 605 led to three genotypes MM (236 bp/236 bp), Mm (236 bp/303 bp) and mm (303 bp/303 bp) in five sheep breeds. The presence (allele R) or absence (allele r) of a Rsa I site at base position 604 led to three genotypes RR (267 bp/267 bp), Rr (267 bp/290 bp) and rr (290 bp/290 bp) in five sheep breeds. Frequencies of MM and RR genotypes were obviously higher, and frequencies of mm and rr genotypes were obviously lower in nonseasonal estrous sheep breeds than in seasonal estrous sheep breeds. Sequencing revealed four mutations (G453T, G612A, G706A, C891T) in mm genotype compared to MM genotype and one mutation (C606T) in rr genotype compared to RR genotype. For polymorphic Mnl I and Rsa I cleavage sites, the differences of genotype distributions were very highly significant (p<0.01) between Small Tail Han ewes and seasonal estrous sheep breeds. In each group, no significant difference (p>0.05) was detected. These results preliminarily showed an association between MM, RR genotypes and nonseasonal estrus in ewes and an association between mm, rr genotypes and seasonal estrus in ewes.

The Signaling Mechanism of Contraction Induced by ATP and UTP in Feline Esophageal Smooth Muscle Cells

  • Kwon, Tae Hoon;Jung, Hyunwoo;Cho, Eun Jeong;Jeong, Ji Hoon;Sohn, Uy Dong
    • Molecules and Cells
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    • v.38 no.7
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    • pp.616-623
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    • 2015
  • P2 receptors are membrane-bound receptors for extracellular nucleotides such as ATP and UTP. P2 receptors have been classified as ligand-gated ion channels or P2X receptors and G protein-coupled P2Y receptors. Recently, purinergic signaling has begun to attract attention as a potential therapeutic target for a variety of diseases especially associated with gastroenterology. This study determined the ATP and UTP-induced receptor signaling mechanism in feline esophageal contraction. Contraction of dispersed feline esophageal smooth muscle cells was measured by scanning micrometry. Phosphorylation of $MLC_{20}$ was determined by western blot analysis. ATP and UTP elicited maximum esophageal contraction at 30 s and $10{\mu}M$ concentration. Contraction of dispersed cells treated with $10{\mu}M$ ATP was inhibited by nifedipine. However, contraction induced by $0.1{\mu}M$ ATP, $0.1{\mu}M$ UTP and $10{\mu}M$ UTP was decreased by U73122, chelerythrine, ML-9, PTX and $GDP{\beta}S$. Contraction induced by $0.1{\mu}M$ ATP and UTP was inhibited by $G{\alpha}i_3$ or $G{\alpha}q$ antibodies and by $PLC{\beta}_1$ or $PLC{\beta}_3$ antibodies. Phosphorylated $MLC_{20}$ was increased by ATP and UTP treatment. In conclusion, esophageal contraction induced by ATP and UTP was preferentially mediated by P2Y receptors coupled to $G{\alpha}i_3$ and $G{\alpha}q$ proteins, which activate $PLC{\beta}_1$ and $PLC{\beta}_3$. Subsequently, increased intracellular $Ca^{2+}$ and activated PKC triggered stimulation of MLC kinase and inhibition of MLC phosphatase. Finally, increased $pMLC_{20}$ generated esophageal contraction.

Expression of Recombinant Human Bone morphogenetic protein 2 (hBMP2) in Insect cells

  • Kim, Seong-Wan;Kim, Seong-Ryul;Park, Seung Won;Goo, Tae-Won;Choi, Kwang-Ho
    • International Journal of Industrial Entomology and Biomaterials
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    • v.34 no.1
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    • pp.1-5
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    • 2017
  • Bone morphogenetic protein 2 (BMP2) plays an important role in the development of bone and cartilage. It is involved in the hedgehog pathway, TGF beta signaling pathway, and in cytokine-cytokine receptor interaction. It is involved also in cardiac cell differentiation and epithelial to mesenchymal transition. In this study, We expressed human BMP2 (hBMP2) recombinant protein using Baculovirus Expression Vector System (BEVS) in Sf9 insect cells. The hBMP2 cDNA was cloned into baculovirus transfer vector, pBacgus-4x-1 and recombinant baculovirus was screened out through X-gal and GUS-fusions assay. Western blot analysis shown that molecular weight of hBMP2 recombinant protein was about 44.71 kDa.

Cytochrome P-450 3A4 proximal promoter activity by histone deacetylase inhibitor in HepG2 cell.

  • Kim, Ja-Young;Ahn, Mee-Ryung;Sheen, Yhun-Yhong
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2003.11a
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    • pp.88-88
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    • 2003
  • Cytochrome P-450 3A4 (CYP3A4) is major enzyme in human liver, the role of this is detoxification and metabolizing more than 50% clinical drugs in use. Expression of CYP3A4 is transciptionally regulated by the Pregnenolone X receptor (PXR), of which human form is Steroid and Xenobiotics receptor (SXR). SXR is activated by wide range of endogenous and exogenous compounds, and then induces CYP3A4 gene expression. In the previous study, it has been known that proximal promoter (-864 to +64) does not response to chemical inducers such as pregnenolone 16a-carbonitrile (PCN), Rifampicin, Estrogen in terms of transcription of CYP 3A4 in cultured cells. Here, we developed luciferase reporter gene assay system to detect SXR-based CYP 3A4 transcriptional activity. We have used CYP3A4-Luc plasmid that contains proximal promoter of human CYP3A4 gene upstream of the luciferase gene. We did transient transfection of 3A4-luciferase gene and SXR. In the HepG2 cells transfected with CYP3A4-Luc, when rifampicin treatment was combined with histone deacetylase inhibitor (HDAC Inhibitor), such as Trichostatin A, Hc-toxin and IN 2001 of the luciferase activity was induced 10-20 fold over control.

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Cytochrome P-450 3A4 proximal promoter activity by histone deacetylase inhibitor in HepG2 cell.

  • Kim, Ja-Young;Ahn, Mee-Ryung;Sheen, Yhun-Yhong
    • Proceedings of the Korea Society of Environmental Toocicology Conference
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    • 2003.10a
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    • pp.178-178
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    • 2003
  • Cytochrome P-450 3A4 (CYP3A4) is major enzyme in human liver, the role of this Is detoxification and metabolizing more than 50% clinical drugs in use. Expression of CYP3A4 is transciptionally regulated by the Pregnenolone X receptor (PXR), of which human form is Steroid and Xenobiotics receptor (SXR). SXR is activated by wide range of endogenous and exogenous compounds, and then induces CYP3A4 gene expression. In the previous study, it has been known that proximal promoter (-864 to +64) does not response to chemical inducers such as pregnenolone 16a-carbonitrile (PCN), Rifampicin, Estrogen in terms of transcription of CYP 3A4 in cultured cells. Here, we developed luciferase reporter gene assay system to detect SXR-based CYP 3A4 transcriptional activity. We have used CYP3A4-Luc plasmid that contains proximal promoter of human CYP3A4 gene upstream of the luciferase gene. We did transient transfection of 3A4-luciferase gene and SXR. In the HepG2 cells transfected with CYP3A4-Luc, when rifampicin treatment was combined with histone deacetylase inhibitor (HDAC Inhibitor), such as Trichostatin A, Hc-toxin and IN 2001 of the luciferase activity was induced 10-20 fold over control.

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The rare case of 46,XX testicular disorder of sex development carrying a heterozygous p.Arg92Trp variant in NR5A1

  • Lia Kim;Hwa Young Kim;Jung Min Ko
    • Journal of Genetic Medicine
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    • v.19 no.2
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    • pp.115-119
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    • 2022
  • The 46,XX testicular disorder of sex development (DSD) is a rare condition in which 46,XX individuals develop testicular differentiation and virilization. Translocation of the sex-determining region Y (SRY) onto the X chromosome is the main cause of 46,XX testicular DSD, whereas dysregulation between pro-testis and pro-ovarian genes can induce SRY-negative 46,XX testicular DSD. Nuclear receptor subfamily 5 group A member 1 (NR5A1), a nuclear receptor transcription factor, plays an essential role in gonadal development in XY and XX embryos. Herein, we report the first Korean case of SRY-negative 46,XX testicular DSD with a heterozygous NR5A1 p.Arg92Trp variant. The patient presented with a small penis, bifid scrotum, and bilateral undescended testes. Whole exome sequencing revealed a heterozygous missense variant (c.274C>T) of NR5A1. Our case highlights that NR5A1 gene variants need to be considered important causative factors of SRY-negative non-syndromic 46,XX testicular DSD.

Differences in Epidermal Growth Factor Receptor Gene Mutations and Relationship with Clinicopathological Features in NSCLC Between Uygur and Han Ethnic Groups

  • Zhang, Yan;Wang, Qiang;Han, Zhi-Gang;Shan, Li
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.5
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    • pp.2879-2883
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    • 2013
  • Objective: To investigate differences in mutations of epidermal growth factor receptor (EGFR) gene and relationships with clinicopathological features in patients with non-small cell lung cancer (NSCLC) between Uygur and Han ethnic groups. Methods: The Scorpions amplification refractory mutation system (Scorpions ARMS) was used to measure mutations in exons 18, 19, 20 and 21 of the EGFR gene in paraffin-embedded tumor tissue from NSCLC cases, and statistical analysis was performed to investigate links with clinicopathological features in different histological types of NSCLC. Results: Results from ARMS testing showed EGFR mutations in tumor tissues from six (6) of 50 NSCLC patients of Uygur ethnic group, with a positive rate of 12.0%; four of them (4) had exon 19 deletion in EGFR, and two (2) had L858R point mutation in exon 21 of EGFR. Statistically significant difference was noted in EGFR genetic mutation between adenocarcinoma and non-adenocarcinoma (P < 0.05), but no differences with gender, age group, smoking status, or stage (P > 0.05). EGFR mutations were detected in tumor tissues from 27 of 49 NSCLC patients of Han ethnic group, with a positive rate of 55.1%; 19 of them had exon 19 deletions, seven (7) had L858R point mutations in exon 21 of EGFR and one (1) had mutations in both exon 18 G719X and exon 20 T790M of EGFR. Statistically significant differences were noted in EGFR genetic mutations between genders and between adenocarcinoma and non-adenocarcinoma (P<0.05), but not with age group, smoking status, or stage (P > 0.05). Conclusion: Statistically significant differences were noted in the positive rates of EGFR genetic mutations in NSCLC patients between Uygur and Han ethnic groups, with lower positive rates for the Uygur cases.

A Method for the Determination of Estrogen Receptor Level in Frozen Sections of Porcine Uterus (냉동절편을 이용한 돼지 자궁내 에스트로겐 수용체의 측정)

  • Yoon, Yong-Dal;Park, Chor-Hong;Lee, Young-Keun
    • Clinical and Experimental Reproductive Medicine
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    • v.16 no.2
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    • pp.131-138
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    • 1989
  • The present study was designed to develop a new method for the determination of estrogen receptor in porcine uterus using frozen sections. Cryostat sections were incubated with $^3H$-estradiol($^3H$-$E_2$) in the presence or absence of diethylstilbestrol(DES) and the radioactivity of 3H-E2 bound to estrogen receptor(ER) was detected. The level of specific estrogen receptor was determined by Scatchard analysis. The highest ratio of specific binding against total binding was achieved in 3 sec. tions(5mm x 5mm) which was corresponded to lOO${\mu}$/ml protein concentration. Optimal binding was obtained during incubation with $^3H$-$E_2$ for 30 minutes at 23$^{\circ}C$ after treatment of sections with acetone for 20 seconds. Three time-washing of sections was proved to be appropriate for the removal of unbound 3H-E2. 200-fold molar excess of DES was substituted for the binding of $^3H$-$E_2$ to ER sufficiently(binding efficiency of 54.8%). ER was saturated with 4nM of $^3H$-$E_2$ and its dissociation constant was 0.1nM. ER assay using frozen sections(Histological radioreceptor assay, HRRA) was significantly correlated with radioreceptor assay for estradiol(RRA, 0.976 , p

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Analysis of Androgen Receptor Gene by Capillary Gel Eelectrophoresis (모세관 젤 전기영동을 이용한 안드로젠 수용체 유전자 분석)

  • Kim, Yong-Seong;Baek, Seung-Gwon;Gang, Chung-Mu;Gang, Dae-Cheon;Lee, Su-Man;Choe, Byeong-Ok;Jeong, Gi-Hwa;Choe, Gyu-Seong
    • Journal of the Korean Chemical Society
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    • v.50 no.1
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    • pp.37-45
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    • 2006
  • gel electrophoresis (CGE) with poly(ethylene oxide) has been applied to the measurement of CAG repeat number in Androgen receptor (AR) gene related to male infertility. Non-linear regression analysis was performed using the standard X174 RF/Hae III, 100bp step ladder DNA in order to investigate the exact number of CAG repeat. For 79 Korean infertile males and 89 controls, CAG repeats at exon 1 in AR gene was compared and analyzed by CGE. It turned out that CAG repeat numbers were 24.972.6 range, 17-29) for the infertile male, and 23.992.4 range, 18-29) for the control, respectively. P value (0.018) was less then 0.05, meaning that the result was statistically meaningful.