• Title/Summary/Keyword: $K^+-Dependent$ phosphatase

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Induction of G2/M Arrest and Apoptosis by the Methanol Extract of Typha orientalis in Human Colon Adenocarcinoma HT29 Cells (포황 메탄올 추출물에 의한 인체 대장암 세포주 HT29의 G2/M Arrest 및 Apoptosis 유발)

  • Jin, Soojung;Yun, Seung-Geun;Oh, You Na;Lee, Ji-Young;Park, Hyun-Jin;Jin, Kyong-Suk;Kwon, Hyun Ju;Kim, Byung Woo
    • Microbiology and Biotechnology Letters
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    • v.41 no.4
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    • pp.425-432
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    • 2013
  • Typha orientalis, also known as bulrush or cattail, is a perennial herbaceous plant found in freshwater wetlands and has been widely used in constructed wetlands for wastewater treatment. Recent data has revealed that SH21B, a mixture composed of seven herbs including T. orientalis, exhibited an anti-adipogenic activity by the inhibition of the expression of adipogenic regulators. However, the anti-cancer effect of T. orientalis and its molecular mechanisms remain unclear. In this study, we evaluated the anti-cancer effect and its mechanism in the methanol extract of T. orientalis (METO) on human colon carcinoma HT29 cells. It was found that METO treatment showed cytotoxic activity in a dose-dependent manner, and induced G2/M cell cycle arrest and apoptosis in HT29 cells. The induction of G2/M arrest by METO was associated with the up-regulation of phospho-Cdc2 (Tyr15), an inactive form of Cdc2 and the down-regulation of Cdc25c phosphatase. METO also induced tumor suppressor p53 and cyclin-dependent kinase inhibitor p21 (WAF1/CIP1) expression. In addition, METO-induced apoptosis was characterized by the proteolytic activation of caspase-3, degradation of poly ADP ribose polymerase (PARP), and up-regulation of death receptor FAS and pro-apoptotic Bax expression. Collectively, these results indicate that the cell cycle inhibition and apoptosis induction of METO in HT29 cells allows for the possibility of its use in anti-cancer therapies.

HYPOPHOSPHATEMIC RICKETS : CASE REPORT (저인산혈증성 구루병 환아의 증례 보고)

  • Park, Yoon-Hee;Choi, Byung-Jai;Lee, Jong-Gap
    • Journal of the korean academy of Pediatric Dentistry
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    • v.27 no.1
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    • pp.108-112
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    • 2000
  • Hypophosphatemic rickets is lack of reponse to physiologic doses of vitamin D, different from the vitamin D-dependent rickets. It is inherited in an X-linked dominant fashion. The prime features of this disorder are lowered serum phosphate levels, elevated serum alkaline phosphatase and normal serum calcium levels. The dental manifestation often include apical radiolucencies, abscess and fistulas of clinically sound teeth. Dental radiographs show ricketic bone trabeculations, abscent or abnormal lamina dura and abnormal cementum. This case which was diagnosed to hypophosphatemic rickets, showed multiple spontaneous periapical abscess and gingival fistula enlarged pulp chambers, extension of the pulp horns into the cusp tips and delayed eruption.

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Regulation of BAD Protein by PKA, PKCδ and Phosphatases in Adult Rat Cardiac Myocytes Subjected to Oxidative Stress

  • Cieslak, Danuta;Lazou, Antigone
    • Molecules and Cells
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    • v.24 no.2
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    • pp.224-231
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    • 2007
  • $H_2O_2$, as an example of oxidative stress, induces cardiac myocyte apoptosis. Bcl-2 family proteins are key regulators of the apoptotic response while their functions can be regulated by post-translational modifications including phosphorylation, dimerization or proteolytic cleavage. In this study, we examined the role of various protein kinases in regulating total BAD protein levels in adult rat cardiac myocytes undergoing apoptosis. Stimulation with 0.1 mM $H_2O_2$, which induces apoptosis, resulted in a marked down-regulation of BAD protein, which is attributed to cleavage by caspases since it can be restored in the presence of a general caspase inhibitor. Inhibition of PKC, p38-MAPK, ERK1/2 and PI-3-K did not influence the reduced BAD protein levels observed after stimulation with $H_2O_2$. On the contrary, inhibition of PKA or specifically $PKC{\delta}$ resulted in up-regulation of BAD. Decreased caspase 3 activity was observed in $H_2O_2$ treated cells after inhibition of PKA or $PKC{\delta}$ whereas inhibition of PKA also resulted in improved cell survival. Furthermore, addition of okadaic acid to inhibit selected phosphatases resulted in enhanced BAD cleavage. These data suggest that, during oxidative stress-induced cardiac myocyte apoptosis, there is a caspase-dependent down-regulation of BAD protein, which seems to be regulated by coordinated action of PKA, $PKC{\delta}$ and phosphatases.

Effect of p-Phenylenediamine Application to Rat Skin on the Liver Oxygen Free Radical Systems

  • Park, Hye-Jung;Lee, Sang-Hee;Yoon, Chong-Guk
    • Biomedical Science Letters
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    • v.9 no.2
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    • pp.75-84
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    • 2003
  • To evaluate the influence of hepatic oxygen free radical systems on liver injury by topical p-phenylenediamine (PPD) application on rat skin, PPD (25 mg/16.5 $\textrm{cm}^2$) was topically applied to the abdominal region 5 times every other day and sacrificed. By PPD treatment, increasing rate of liver weight/body weight (%), serum activities of alanine aminotransferase and aspartate aminotransferase and decreasing rate of microsomal glucose-6-phosphatase activity were higher in the rats fed tungstate supplemented diet than those fed a standard diet. These findings indicate that group fed tungstate supplemented diet have more severe liver injury compared with group fed standard diet on topical PPD application. However, the activities of oxygen free radical generating enzymes such as xanthine oxidase (XO) and cytochrome P450 dependent aniline hydroxylase and those of oxygen free radical scavenging enzymes were not found to be different between these two animal groups. In the present study, a novel monitoring method to detect the generating of oxygen free radicals in liver extract was devised. Throughout this method, the oxidized PPD produced by oxygen free radicals was determined colorimetrically. The increasing rate of PPD oxidation by liver homogenate was higher in tungstate fed animals than in standard diet fed ones. Among the fractionations of liver extract, the mitochondrial and postmitochondrial fractions in the liver extract of tungstate fed animals led to a higher availability of PPD oxidation by PPD treatment compared with standard diet fed ones. In conclusion, these results suggest that an enhanced liver injury in tungstate fed animals treated with PPD may be due to oxygen free radicals produced in other systems except oxygen free radicals generating from cytosolic XO system. Especially, oxidative availability by PPD can be used for oxygen free radical detection in some tissue.

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Comparative Study on the Transport Characteristics of Canalicular Liver Plasma Membrane Vesicles Prepared by Two Different Methods (제조 방법에 따른 간 모세담관막 소포계의 수송 특성 비교)

  • Song, Im-Sook;Chung, Suk-Jae;Shim, Chang-Koo
    • Journal of Pharmaceutical Investigation
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    • v.29 no.1
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    • pp.13-19
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    • 1999
  • Canalicular liver plasma membrane vesicles (cLPM) were prepared according to two different methods (Inoue method and Meier method), and were evaluated for their protein yield, enzyme activity and transport characteristics. No difference was found between the methods in the protein yield (i.e., $0.14{\pm}0.031$ and $0.15{\pm}0.050$ mglg liver for Inoue method and Meier method, respectively). The activity of alkaline phosphatase, a marker enzyme of canalicular membrane, was significantly (P<0.05) higher in the vesicles of Meier method $(3.52{\pm}0.91\;mmol/mg/hr)$than in the vesicles of Inoue method ($2.28{\pm}0.94$ mmol/mg/hr) indicating that more purified cLPM were obtained from Meier method compared with Inoue method. ATP-dependent vesicular uptake of taurocholate and tributylmethylammonium (TBuMA) was observed for vesicles of both methods, and the kinetic parameters responsible for the transport were similar between the vesicles of both methods (for example, $V_{max}:$ 9.72 nmol/mg protein/30sec and $K_m:$ 0.63 mM for Inoue method; $V_{max}:$ 10.1 nmol/mg protein/30sec and $K_m:$ 0.70 mM for Meier method). A pH gradient dependent counter transport of TBuMA was also observed for both vesicles with similar kinetic characteristics. Either the uptake of taurocholate in the absence of ATP or that of TBuMA in the absence of pH gradient, which may represent passive diffusion of respective compound into the vesicles, was more rapid for the vesicles of Meier method than for the vesicles of Inoue method. For example, passive diffusion rate constants $(K_d)$ for TBuMA uptake into the vesicles were 0.00030 and 0.00052\;{\mu}l/mg$ protein/min for the vesicles of Inoue method and Meier method, respectively. It may indicate that more leaky vesicles are obtained form the Meier method compared with the Inoue method. These aspects together with the time necessary to prepare the vesicles (i.e., 8 hr for Inoue method and 23 hr for Meier method) should be considered before selecting an appropriate method for the preparation of cLPM.

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EFFECTS OF $INTERFERON-\gamma$ ON COLLAGEN AND FIBRONECTIN SYNTHESIS IN PRIMARY CULTURED PERIODONTAL LIGAMENT CELLS ($Interferon-\gamma$가 치주인대 세포의 Collagen 및 Fibronectin의 합성과 Alkaline Phosphatase 활성에 미치는 영향)

  • Kim, Gwang-Seok;Sung, Jae-Hyun;Choi, Je-Yong;Ryou, Hyun-Mo
    • The korean journal of orthodontics
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    • v.23 no.2 s.41
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    • pp.229-248
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    • 1993
  • [ $Interferon-\gamma$ ] has been suggested as a cytokine of connective tissue stabilizer. In addition, it has also been demonstrated that this cytokine inhibited bone remodeling activities of the bone derived cells. In order to illuminate the effects of this cytokine in orthodontic force induced bone remodeling, it was administered to primary cultured periodontal ligament cells which have been known to have some osteoblast like characteristics. $Interferon-\gamma$ slightly decreased $[^3H]thymidine$ incorporation rate without a significant change in the total cellular DNA content up to 1000 U/ml, which meant these doses were not cytotoxic to the cell. Total protein synthesis was not influenced by various concentration of interferon-y whether it was determined by the $[^3H]proline$ incorporation rate or by the Lowry smethod. The effect of $interferon-\gamma$ on the individual protein was, however, differential, ie, it increased $[^3H]proline$ incorporation into the noncollagenous protein marginally, while it decreased $[^3H]proline$ incorporation into the collagen, so that it caused dose-dependent suppression of the relative collagen synthesis. On the contrary, the fibronectin synthesis determined by the ELISA was increased by 1000 U/ml of $interferon-\gamma$. The differential effects of the interferon-y on the collagen and fibronectin synthesis exhibited not only their protein level but also the steady state mRNA level. $Interferon-\gamma$ decreased steady state level of ${\alpha}1(I)$ procollagen mRNA significantly, while showing no significant changes in the fibronectin mRNA level. In addition to this, it was also found that indomethacin did not affect on the $interferon-\gamma$ induced collagen decrease in this cell, which meant prostaglandins were not involed in the process of $interferon-\gamma$ induced collagen decrease. So it can be concluded that the incubation of periodontal ligament cells with 1000 U/ml of $interferon-\gamma$ for 24 hr showed differential effects on the type I collagen and fibronectin gene expression. The decrease in relative collagen synthesis in the protein level was related with decrease in the steady state level of mRNA, while the increase in the fibronectin synthesis in the protein level was not correlated with the mRNA level.

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Characteristics of p-Aminohippurate (PAH) Transport in Basolateral Membrane Vesicles of Rabbit Kidney Cortex -Effect of Anion- (신장 피질 기저막 소포에서 p-Aminohippurate 이동의 특성에 대한 연구 -음이온의 효과-)

  • Lee, Sang-Ho;Chung, Jin-Sup;Kim, Yong-Keun
    • The Korean Journal of Physiology
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    • v.20 no.2
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    • pp.225-235
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    • 1986
  • Effects of anions on p-Aminohippurate (PAH) transport across the basolateral membrane (BLM) were studied. Basolateral membrane vesicles were isolated from rabbit renal cortex by using a self-orienting Percoll-gradient centrifugation and $Mg^{2+}-precipitation$. The characteristics of the membrane vesicles was examined by marker enzyme activity, membrane orientation and transport studies. The Na-K-ATPase activity in the fraction containing BLM vesicles was enriched 9·fold, and the alkaline phosphatase activity in the fraction containing BBM vesicles was increased 9-fold, compared with those of the homogenate. The transport properties of the two membrane preparations were studied by a rapid filtration technique. The uptake of PAH by BLM was sensitive to changes in medium osmolarity and inhibited by probenecid. When the uptake of $50{\mu}M$ PAH in voltage-clamped BLM vesicles was determined in the presence of various anions in the incubation medium, cis inhibitions by $SO_4\;and\;SSO_3$ were observed in the presence of sodium gradient (out>in). Sodium-dependent PAH uptake was inhibited competitively by external $SO_4$ PAH uptake in BLM vesicles loaded with 20 mM acetate and $SO_4\;or\;200\;{\mu}M$ PAH was significantly stimulated as compared with unloaded vesicles. The extent of trans-stmulation of PAH uptake by $SO_4$. was increased with the inside concentration of $SO_4$. This trans-stimulatory effect by $SO_4$, was observed to be additive in the presence of Na gradient and completely inhibited by 2 mM probenecid and 1 mM SITS. These results demonstrate that PAH/anion exchange is present in BLM of renal cortex and in this exchange mechanism inorganic as well as organic anions are involved as substrates.

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Osteogenic Potency of Nacre on Human Mesenchymal Stem Cells

  • Green, David W.;Kwon, Hyuk-Jae;Jung, Han-Sung
    • Molecules and Cells
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    • v.38 no.3
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    • pp.267-272
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    • 2015
  • Nacre seashell is a natural osteoinductive biomaterial with strong effects on osteoprogenitors, osteoblasts, and osteoclasts during bone tissue formation and morphogenesis. Although nacre has shown, in one study, to induce bridging of new bone across large non-union bone defects in 8 individual human patients, there have been no succeeding human surgical studies to confirm this outstanding potency. But the molecular mechanisms associated with nacre osteoinduction and the influence on bone marrow-derived mesenchymal stem cells (BMSC's), skeletal stem cells or bone marrow stromal cells remain elusive. In this study we highlight the phenotypic and biochemical effects of Pinctada maxima nacre chips and the global nacre soluble protein matrix (SPM) on primary human bone marrow-derived stromal cells (hBMSCs) in vitro. In static co-culture with nacre chips, the hBMSCs secreted Alkaline phosphatase (ALP) at levels that exceeded bone morphogenetic protein (rhBMP-2) treatment. Concentrated preparation of SPM applied to Stro-1 selected hBMSC's led to rapid ALP secretions, at concentrations exceeding the untreated controls even in osteogenic conditions. Within 21 days the same population of Stro-1 selected hBMSCs proliferated and secreted collagens I-IV, indicating the premature onset of an osteoblast phenotype. The same SPM was found to promote unselected hBMSC differentiation with osteocalcin detected at 7 days, and proliferation increased at 7 days in a dose-dependent manner. In conclusion, nacre particles and nacre SPM induced the early stages of human bone cell differentiation, indicating that they may be promising soluble factors with osteoinductive capacity in primary human bone cell progenitors such as, hBMSC's.

Effect of Taraxacum Mongolicum Extract on Serum Heavy Metal Levels and Blood Parameters of Albino Rats Exposed to Lead and Mercury (포공영 추출물이 납 및 수은에 노출된 랫드 혈청의 중금속 및 혈액지표에 미치는 영향)

  • Lee, Keyong-Ho;Rhee, Ki-Hyeong
    • Korean Journal of Environmental Agriculture
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    • v.31 no.3
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    • pp.264-270
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    • 2012
  • BACKGROUND: The purpose of this study was that serum metabolic and hematological variables were measured to investigate the detoxication effect of Taraxacum mongolicum extract on male albino rat exposed with lead and mercury. METHODS AND RESULTS: For this study, Pb and Hg-exposed( 50 ppm) albino rats was used, and the treatments were carried out in three doses of 100 mg/kg, 200 mg/kg and 500 mg/kg as dry weight of T. mongolicum extract. T. mongolicum extract could improved the body weight gain and feed efficiency ratio, except to food intake. The levels of biochemical factors elevated by Pb-Hg mix exposure, which are Bilirubin, Alkaline phosphatase(ALP), glutamic oxaloacetate transaminase(GOT), glutamic pyruvate transaminase (GPT), lactate dehydrogenase(LDH), ceatinine and blood urea nitrogen(BUN), were significantly reduced in all treated groups as compared to Pb-Hg mix exposure alone. T. mongolicum extract was shown to suppress the accumulation of Hg and Pb in serum by dose dependent manner. CONCLUSION: Therefore, this study suggest that T. mongolicum extract might have the potential effect to minimize the toxic effects of Pb and Hg.

A Novel Calcineurin-interacting Protein, CNP-3, Modulates Calcineurin Deficient Phenotypes in Caenorhabditis elegans

  • Kim, Yun Hee;Song, Hyun-Ok;Ko, Kyung Min;Singaravelu, Gunasekaran;Jee, Changhoon;Kang, Junsu;Ahnn, Joohong
    • Molecules and Cells
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    • v.25 no.4
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    • pp.566-571
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    • 2008
  • Calcineurin (Cn) is a calcium/calmodulin-dependent serine/threonine protein phosphatase that has diverse functions in different cell types and organisms. We screened proteins interacting with the C. elegans CnA homolog, TAX-6, by the yeast two-hybrid system. CNP-3 (Calcineurin interacting protein-3) is a novel protein that physically interacts with the catalytic domain of TAX-6. It is strongly expressed in the nuclei of intestine, hypodermis, dorsal uterine regions and spermatheca. Expression begins around the 60-cell stage and proceeds during all larval stages and the adult. To elucidate the biological function of cnp-3 we isolated a cnp-3 deletion mutant. Since CNP-3 binds CnA, we looked at factors associated with calcineurin loss-of-function mutants, such as brood size, body size, serotonin- and levamisole-mediated egg-laying behavior. The cnp-3(jh145) single mutant had no gross defects compared to wild-type animal. However, the phenotypes of the double mutants, tax-6(p675);cnp-3(jh145) and cnb-1(jh103);cnp-3(jh145), were more severe in terms of brood size, body size and serotonin-mediated egg-laying defects than tax-6(p675) and cnb-1(jh103), respectively. These results suggest that dysfunction of cnp-3 enhances certain calcineurin loss-of-function phenotypes in C. elegans.