1.Activation of phosphatidylinositol 4, 5-biphosphate(PIP2) cascade by thyroid stimulating antibody.
Jae Hoon CHUNG ; Bo Youn CHO ; Jae Seok JEON ; Kyong Soo PARK ; Seong Yeon KIM ; Hong Kyu LEE ; Chang Soon KOH
Journal of Korean Society of Endocrinology 1993;8(4):422-431
No abstract available.
Immunoglobulins, Thyroid-Stimulating*
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Phosphatidylinositols*
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Thyroid Gland*
2.PTEN Methylation Dependent Sinonasal Mucosal Melanoma.
Sang Hee LEE ; Mi Ryung ROH ; Beodeul KANG ; Kyu Hyun PARK ; Soo Hee KIM ; Sang Eun LEE ; Sun Young RHA
Cancer Research and Treatment 2016;48(2):853-858
Sinonasal mucosal melanoma (SMM) is an aggressive and rare type of melanoma. Although the classic RAS-RAF-MEK pathway is thought to be the main pathway involved in melanoma pathogenesis, genetic alterations in the phosphatidylinositol 3-kinase-AKT pathway, including PTEN-regulated signaling, are also thought to contribute. So far, data regarding altered PTEN expression and epigenetic mechanism of PTEN silencing in development of SMM is extremely limited. Herein we report on a case of SMM with liver and bone metastases with an epigenetic alteration of PTEN. Results of mutation analysis for BRAF, NRAS, HRAS, KRAS, PIK3CA, c-Kit, and PTEN were negative; however, methylation of PTEN CpG islands was observed. Our case not only supports PTEN as a major tumor suppressor involved in melanoma tumorigenesis, but also a potential epigenetic mechanism of PTEN silencing in development of SMM.
Carcinogenesis
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CpG Islands
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Epigenomics
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Liver
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Melanoma*
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Methylation*
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Neoplasm Metastasis
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Phosphatidylinositols
3.PTEN Methylation Dependent Sinonasal Mucosal Melanoma.
Sang Hee LEE ; Mi Ryung ROH ; Beodeul KANG ; Kyu Hyun PARK ; Soo Hee KIM ; Sang Eun LEE ; Sun Young RHA
Cancer Research and Treatment 2016;48(2):853-858
Sinonasal mucosal melanoma (SMM) is an aggressive and rare type of melanoma. Although the classic RAS-RAF-MEK pathway is thought to be the main pathway involved in melanoma pathogenesis, genetic alterations in the phosphatidylinositol 3-kinase-AKT pathway, including PTEN-regulated signaling, are also thought to contribute. So far, data regarding altered PTEN expression and epigenetic mechanism of PTEN silencing in development of SMM is extremely limited. Herein we report on a case of SMM with liver and bone metastases with an epigenetic alteration of PTEN. Results of mutation analysis for BRAF, NRAS, HRAS, KRAS, PIK3CA, c-Kit, and PTEN were negative; however, methylation of PTEN CpG islands was observed. Our case not only supports PTEN as a major tumor suppressor involved in melanoma tumorigenesis, but also a potential epigenetic mechanism of PTEN silencing in development of SMM.
Carcinogenesis
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CpG Islands
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Epigenomics
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Liver
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Melanoma*
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Methylation*
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Neoplasm Metastasis
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Phosphatidylinositols
4.A Study of the Pathway of Nitric Oxide Production by Nitroglycerin in Trabecular Meshwork Cells.
Journal of the Korean Ophthalmological Society 2013;54(9):1429-1434
PURPOSE: To investigate the effects of nitroglycerin on the production of nitric oxide and its related pathway in cultured human trabecular meshwork cells (HTMC). METHODS: Primarily cultured HTMC were exposed to 10 nM nitroglycerin using 1% serum-containing media for 30 minutes. The production of nitric oxide was assessed with the Griess assay and expressions of eNOS mRNA was assessed with RT-PCR. Additionally, the cells were exposed to wortmanin and Akt1/2 kinase inhibitor to investigate the mechanism related to the production of nitric oxide. RESULTS: Nitroglycerin increased the production of nitric oxide (p < 0.05) accompanied with increased expression of eNOS mRNA. The increased production of nitric oxide and eNOS mRNA was inhibited by wortmanin and Akt1/2 kinase inhibitor. CONCLUSIONS: Low-dose nitroglycerin increased the production of nitric oxide accompanied by increased eNOS activity. Nitroglycerin drives eNOS activation via the phosphatidylinositol 3-kinase/protein kinase B pathway.
Humans
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Nitric Oxide
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Nitroglycerin
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Phosphatidylinositols
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Phosphotransferases
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RNA, Messenger
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Trabecular Meshwork
5.Mutation Analysis of PIG-A Gene in Korean Patients with Paroxysmal Nocturnal Hemoglobinuria.
Jong Hyun YOON ; Han Ik CHO ; Sung Sup PARK ; Yoon Hwan CHANG
Korean Journal of Hematology 2000;35(2):143-149
BACKGROUND: Paroxysmal nocturnal hemoglobinuria (PNH) is caused by deficient biosynthesis of the glycosylphosphatidylinositol (GPI) anchor in hemopoietic stem cells. Mutation of phosphatidyl inositol glycan class A (PIG-A) gene, an X-linked gene that participates in the first step of GPI anchor biosynthesis, is responsible for PNH. Characteristics of somatic mutation of PIG-A gene in the Korean patients with PNH and their relationships to clinical characteristics were analyzed. METHODS: Twenty five patients with PNH and a donor of bone marrow transplantation were selected. Ham tests, sucrose hemolysis tests and CD59 expressions of erythrocytes and granulocytes were performed to confirm diagnosis. Dideoxy fingerprinting (ddF) was used to screen mutations, and direct sequencing of DNA was performed to characterize the mutations. RESULTS: The mutations of PIG-A gene were found in twelve cases and ten of them were novel mutations. There were five deletions, six substitutions and a insertion. Therewere six premature terminations, three abnormal splicings, a missense and two nonsense mutations. There were six point mutations and six frameshift mutations. Five cases of hypoplastic PNH showed mutations only in exons, but three in seven cases of hemolytic PNH showed mutations in introns. Two cases with symptoms of venous thrombosis showed mutations in exon 3. CONCLUSION: There were ten novel mutations among twelve mutations in the Korean patients with PNH and characteristics of the mutations were variable without any remarkable hot spot in sites and types. The characteristics of mutation were not correlated with the results of clinical courses of the patients with PNH.
Bone Marrow Transplantation
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Codon, Nonsense
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Dermatoglyphics
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Diagnosis
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DNA
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Erythrocytes
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Exons
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Frameshift Mutation
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Genes, X-Linked
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Glycosylphosphatidylinositols
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Granulocytes
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Hemoglobinuria, Paroxysmal*
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Hemolysis
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Humans
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Introns
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Phosphatidylinositols
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Point Mutation
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Stem Cells
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Sucrose
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Tissue Donors
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Venous Thrombosis
6.Control of ovarian primordial follicle activation.
Clinical and Experimental Reproductive Medicine 2012;39(1):10-14
The ovarian follicles develop initially from primordial follicles. The majority of ovarian primordial follicles are maintained quiescently as a reserve for the reproductive life span. Only a few of them are activated and develop to an advanced follicular stage. The maintenance of dormancy and activation of primordial follicles are controlled by coordinated actions of a suppressor/activator with close communications with somatic cells and intra-oocyte signaling pathways. Many growth factors and signaling pathways have been identified and the transforming growth factor-beta superfamily plays important roles in early folliculogenesis. However, the mechanism of maintaining the dormancy and survival of primordial follicles has remained unknown for decades. Recently, since the first finding that all primordial follicles are activated prematurely in mice deficient forkhead box O3a, phosphatidylinositol 3 kinase/phosphatase and tensin homolog (PTEN) signaling pathway was reported to be important in the regulation of dormancy and initial follicular activation. With these informations on early folliculogenesis, clinical application can be expected such as in vitro maturation of immature oocytes or in vitro activation of follicles by PTEN inhibitor in cryopreserved ovarian cortical tissues for fertility preservation.
Animals
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Female
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Fertility Preservation
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Intercellular Signaling Peptides and Proteins
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Mice
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Microfilament Proteins
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Oocytes
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Ovarian Follicle
;
Phosphatidylinositols
7.Control of ovarian primordial follicle activation.
Clinical and Experimental Reproductive Medicine 2012;39(1):10-14
The ovarian follicles develop initially from primordial follicles. The majority of ovarian primordial follicles are maintained quiescently as a reserve for the reproductive life span. Only a few of them are activated and develop to an advanced follicular stage. The maintenance of dormancy and activation of primordial follicles are controlled by coordinated actions of a suppressor/activator with close communications with somatic cells and intra-oocyte signaling pathways. Many growth factors and signaling pathways have been identified and the transforming growth factor-beta superfamily plays important roles in early folliculogenesis. However, the mechanism of maintaining the dormancy and survival of primordial follicles has remained unknown for decades. Recently, since the first finding that all primordial follicles are activated prematurely in mice deficient forkhead box O3a, phosphatidylinositol 3 kinase/phosphatase and tensin homolog (PTEN) signaling pathway was reported to be important in the regulation of dormancy and initial follicular activation. With these informations on early folliculogenesis, clinical application can be expected such as in vitro maturation of immature oocytes or in vitro activation of follicles by PTEN inhibitor in cryopreserved ovarian cortical tissues for fertility preservation.
Animals
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Female
;
Fertility Preservation
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Intercellular Signaling Peptides and Proteins
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Mice
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Microfilament Proteins
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Oocytes
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Ovarian Follicle
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Phosphatidylinositols
8.Expression, purification and phosphoinositide binding specifity of recombinant human SNX7 expressed in Escherichia coli.
Zhan FENG ; Tingting XU ; Jinxin XU
Chinese Journal of Biotechnology 2014;30(9):1436-1445
Sorting nexins (SNXs) are a large group of proteins that contain Phox (PX) domain and involve in regulating endocytosis and endosome sorting. SNX7, a member of SNXs family, contains a PX domain and a BAR domain. In zebrafish, SNX7 is a liver-enriched anti-apoptotic protein and indispensible for the liver development. A fragment of SNX7 cDNA ((px-bar)snx7), encoding the PX domain and the BAR domain, was inserted into the expressing vector p28a, transformed into E. coli Rosseta 2 (DE3), and then induced by isopropyl β-D-1-Thiogalactopyranoside (IPTG). After affinity, ion exchange and gel filtration purification, the purity of (PX-BAR)SNX7 reached over 95%. Dynamic light scattering (DLS) experiment indicated that (PX-BAR)SNX7 was homogeneous in solution. Lipid overlay assay showed that (PX-BAR)SNX7 can bind to PtdIns(5)P, PtdIns(4,5)P2 and PtdIns(3,4,5)P3.
Escherichia coli
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metabolism
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Genetic Vectors
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Humans
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Phosphatidylinositols
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metabolism
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Recombinant Proteins
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biosynthesis
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Sorting Nexins
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biosynthesis
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Substrate Specificity
9.Lipidomic analysis of plasma lipids composition changes in septic mice.
Won Gyun AHN ; Jun Sub JUNG ; Dong Keun SONG
The Korean Journal of Physiology and Pharmacology 2018;22(4):399-408
A lipidomic study on extensive plasma lipids in bacterial peritonitis (cecal ligation and puncture, CLP)-induced sepsis in mice was done at 24 h post-CLP. The effects of administration of lysophosphatidylcholine (LPC) and lysophosphatidic acid (LPA), compounds known to have beneficial effects in CLP, on the sepsis-induced plasma lipid changes were also examined. Among the 147 plasma lipid species from 13 lipid subgroups (fatty acid [FA], LPA, LPC, lysophosphatidylethanolamine [LPE], phosphatidic acid [PA], phosphatidylcholine [PC], phosphatidylethanolamine [PE], phosphatidylinositol [PI], monoacylglyceride [MG], diacylglyceride [DG], triacylglyceride [TG], sphingomyelin [SM], and ceramide [Cer]) analyzed in this study, 40 and 70 species were increased, and decreased, respectively, in the CLP mice. Treatments with LPC and LPA affected 14 species from 7 subgroups, and 25 species from 9 subgroups, respectively. These results could contribute to finding the much needed reliable biomarkers of sepsis.
Animals
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Biomarkers
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Ligation
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Lysophosphatidylcholines
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Mice*
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Peritonitis
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Phosphatidic Acids
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Phosphatidylcholines
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Phosphatidylinositols
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Plasma*
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Punctures
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Sepsis
10.Regulation of Adenosine-activated GIRK Channels by Gq-coupled Receptors in Mouse Atrial Myocytes.
The Korean Journal of Physiology and Pharmacology 2010;14(3):145-150
Adenosine (Ado) is an important mediator of the endogenous defense against ischemia-induced injury in the heart. The action of Ado is mediated by activation of G protein-gated inwardly rectifying K+ (GIRK) channels. In turn, GIRK channels are inhibited by reducing phosphatidylinositol 4,5-bisphosphate (PIP2) through Gq protein-coupled receptors (GqPCRs). We previously found that GIRK channels activated by acetylcholine, a muscarinic M2 acetylcholine receptor agonist, are inhibited by GqPCRs in a receptor-specific manner. However, it is not known whether GIRK channels activated by Ado signaling are also regulated by GqPCRs. Presently, this was investigated in mouse atrial myocytes using the patch clamp technique. GIRK channels were activated by 100 micrometer Ado. When Ado was repetitively applied at intervals of 5~6 min, the amplitude of second Ado-activated GIRK currents (I(K(Ado))) was 88.3+/-3.7% of the first I(K(Ado)) in the control. Pretreatment of atrial myocytes with phenylephrine, endothelin-1, or bradykinin prior to a second application of Ado reduced the amplitude of the second I(K(Ado)) to 25.5+/-11.6%, 30.5+/-5.6%, and 96.0+/-2.7%, respectively. The potency of I(K(Ado)) inhibition by GqPCRs was different with that observed in acetylcholine-activated GIRK currents (I(K(ACh))) (endothelin-1>phenylephrine>bradykinin). I(K(Ado)) was almost completely inhibited by 500 micrometer of the PIP2 scavenger neomycin, suggesting low PIP2 affinity of I(K(Ado)). Taken together, these results suggest that the crosstalk between GqPCRs and the Ado-induced signaling pathway is receptor-specific. The differential change in PIP2 affinity of GIRK channels activated by Ado and ACh may underlie, at least in part, their differential responses to GqPCR agonists.
Acetylcholine
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Adenosine
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Animals
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Bradykinin
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Carotenoids
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Endothelin-1
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Heart
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Mice
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Muscle Cells
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Neomycin
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Oxygenases
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Phenylephrine
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Phosphatidylinositols