• 제목/요약/키워드: Protein phosphatase 2A

검색결과 520건 처리시간 0.024초

골형태형성단백질이 백서치주인대세포와 두개관세포에 미치는 영향 (A Study of the Effects of Bone Morphogenetic Protein on the Characteristics of Rat Periodontal Ligament and Calvaria Cells)

  • 최진근;이만섭;권영혁;허익
    • Journal of Periodontal and Implant Science
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    • 제29권4호
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    • pp.765-785
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    • 1999
  • Bone morphogenetic protein-2/4 (BMP-2/4) are members of Transforming Growth $Factor-{\beta}\;(TGF-{\beta})$ superfamily and they may differentiate the osteoprogenitor cell and induce formation of cartilage and bone in vivo. This study was performed to investigate the effects of bone morphogenetic protein-2/4 on the characteristics of rat periodontal ligament cells(RPDL) and rat calvaria cells(RCV). In the control group, the cells were cultured alone with Dulbeco's Modified Eagle's Medium contained with 20% fetal bovine serum, $100{\mu}/ml$ penicillin, $100{\mu}/ml$ streptomycin. In the experimental groups, recombinant human bone morphogenetic protein-2/4 (25ng, 100ng, 250ng/ml) were added into the above culture condition. And then each group was characterized by examing the cell proliferation at 1, 2, 3, 5, 7th day, the amount of total protein synthesis and alkaline phosphatase activity at 2, 5, 7th day. And also, the calcified nodule was examed. The results were as follows ; 1 . Both RCV and RPDL cells in both control and experimental groups proliferated during the entire experimental period, but there is no stastically significant difference according to the BMP-2/4 concentration. 2 . Amount of total protein synthesis of both cells in both groups was steadily increased until 5th day, but all experimental groups were significantly different from the control group at 7th day. 3. Alkaline phosphatase activity of both cells in both groups was increased during the entire experiment period. In RCV cells, the experimental group treated with 100ng/ml and 250ng/ml BMP-2/4 were significantly different from the control group at 7th day. In RPDL cells, the experimental group treated with 100ng/ml and 250ng/ml BMP-2/4 were significantly different from the control group at 5th day, and all experimental groups were significantly different from the control group at 7th day. 4. In the both of the cultured Rat Periodontal ligament and calvaria cell treated with BMP-2/4 to compared with control group, it revealed more rapid cell polarization, cell aggregation and hyperchromatic stained on HE agent, and even though only 1 day treated with BMP-2/4 both RPDL and RCV showed more rapid cell reaction than control group. More sensivitve cell reaction of RCV were observed than RPDL in this experiment. From the above results, we could conclude that BMP-2/4 influenced the induction, proliferation and differentiation of bone forming cells

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Partial Purification of Protein X from the Pyruvate Dehydrogenase Complex of Bovine Kidney

  • 류재하;허재욱;홍성열;송병준
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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    • pp.260-260
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    • 1994
  • Mammalian pyruvate dehydrogenase complex(PDC) enzyme consists of multiple oopies of three major oligomeric enzymes-El, E2 E3. And protein X is one of the enzymatic constituents which is tightly bound to E2 subunit This complex enzyme is responsible for the oxidative decarboxylation of pyruvate producing of acetyl CoA which is a key intermediate for the entry of carbohydrates into the TCA cycle for its complete metabolic conversion to CO$_2$. And the overall activity of the complex enzyme is regulated via covalent nodification of El subunit by a El specific phosphatase ad kinase. Protein X has lipoyl moiety that undergoes reduction and acetylation during ezymatic reaction and has been known h be involved in the binding of E3 subunit to E2 core and in the regulatory activity of kinase. The purification of protein X has not been achieved majorly because of its tight binding to E2 subunit The E2-protein X subcomplex was obtained by the established methods and the detachment of protein X from E2 was accomplished in the 0.1M borate buffer containing 150mM NaCl. During the storage of the subcomplex in frozen state at -70$^{\circ}C$, the E2 subunit was precipitated and the dissociated protein X was obtained by cntrifegation into the supernatant The verification of protein X was accomplished by (1)the migration on SDS-PAGE, (2)acetylation by 〔2$\^$-l4/C〕 pyruvate, and (3)internal amino acid sequence analysis of tryptic digested enzyme.

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Toll-Like Receptor 2 매개 Dual-Specificity Phosphatase 4 발현에서 Extracellular Signal-Regulated Kinase 1/2와 활성산소의 역할 (Role of Extracellular Signal-Regulated Kinase 1/2 and Reactive Oxygen Species in Toll-Like Receptor 2-Mediated Dual-Specificity Phosphatase 4 Expression)

  • 김소연;백석환
    • Journal of Yeungnam Medical Science
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    • 제30권1호
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    • pp.10-16
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    • 2013
  • Background: Toll-like receptors (TLRs) are well-known pattern recognition receptors. Among the 13 TLRs, TLR2 is the most known receptor for immune response. It activates mitogen-activated protein kinases (MAPKs), which are counterbalanced by MAPK phosphatases [MKPs or dual-specificity phosphatases (DUSPs)]. However, the regulatory mechanism of DUSPs is still unclear. In this study, the effect of a TLR2 ligand (TLR2L, Pam3CSK4) on DUSP4 expression in Raw264.7 cells was demonstrated. Methods: A Raw264.7 mouse macrophage cell line was cultured in Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum and 1% antibiotics (100 U/mL penicillin and 100 g/mL streptomycin) at $37^{\circ}C$ in 5% $CO_2$. TLR2L (Pam3CSK4)-mediated DUSP4 expressions were confirmed with RT-PCR and western blot analysis. In addition, the detection of reactive oxygen species (ROS) was measured with lucigenin assay. Results: Pam3CSK4 induced the expression of DUSP1, 2, 4, 5 and 16. The DUSP4 expression was also increased by TLR4 and 9 agonists (lipopolysaccharide and CpG ODN, respectively). Pam3CSK4 also induced ERK1/2 phosphorylation and ROS production, and the Pam3CSK4-induced DUSP4 expression was decreased by ERK1/2 (U0126) and ROS (DPI) inhibitors. U0126 suppressed the ROS production by Pam3CSK4. Conclusion: Pam3CSK4-mediated DUSP4 expression is regulated by ERK1/2 and ROS. This finding suggests the physiological importance of DUSP4 in TLR2-mediated immune response.

성장기 암컷 쥐에서 콩 단백질과 Isoflavones가 골 대사에 미치는 영향 (Effects of Soy and Isoflavones on Bone Metabolism in Growing Female Rats)

  • 최미자;조현주
    • Journal of Nutrition and Health
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    • 제36권6호
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    • pp.549-558
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    • 2003
  • The purpose of this study was to determine which differences in the source of protein (soy vs casein) and isoflavones in soy protein are responsible for the differential effects of bone marks and hormones in growing female rats. Forty-two 21-day-old Sprague-Dawley female rats were randomly assigned to one of three groups, consuming casein (control group), soy protein isolate (57 mg isoflavones/100 g diet), or soy protein concentrate (about 1.2 mg isoflavones/100 g diet). All rats were fed on experimental diet and deionized water ad libitum for 9 weeks. Bone formation was measured by serum osteocalcin and alkaline phosphatase (ALP) concentrations. And bone resorption rate was measured by deoxypyridinoline (DPD) crosslinks immunoassay and corrected for creatinine. Serum osteocalcin, growth hormone, estrogen and calcitonin were analyzed using radioimmunoassay kits. Diet did not affect weight gain and mean food intake. Food efficiency ratio was lower in the soy protein groups. The soy isolate group had a higher ALP and osteocalcin concentration and lower crosslinks value than the casein group. Therefore, the soy isolate groups had a higher bone formation/resorption ratio than the casein group. And, the soy group had significantly higher growth hormone than the casein group. The findings of this study suggest that soy protein and isoflavones are beneficial for bone formation in growing female rats. Therefore, exposure to these soy protein and isoflavones early in life may have benefits for osteoporosis prevention.

불화나트륨이 조골세포의 생리적 활성에 미치는 영향 (THE EFFECT OF SODIUM FLUORIDE ON THE PHYSIOLOGICAL ROLE OF OSTEOBLASTIC CELL)

  • 김대업
    • 대한소아치과학회지
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    • 제25권3호
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    • pp.635-648
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    • 1998
  • The clinical use of fluoride with a well known osteogenic action in osteoporotic patients is rational, because this condition is characterized by impaired bone formation. However, its anabolic effect has not been demonstrated well in vitro. The purpose of this study was to investigate the effects of sodium fluoride on the physiological role of osteoblastic cell. Osteoblastic cells were isolated from fetal rat calvaria. The results were as follows : 1. Mineralized nodules were shown in osteoblastic cell cultures, which had been maintained in the presence of ascorbic acid and ${\beta}-glycerophosphate$ up to 21 days. When cultures were treated with pulses of 48 hr duration before apparent mineralization was occurring, 2-fold increased in their number was detected. 2. Alkaline phosphatase activity of osteoblastic cells was inhibited by sodium fluoride in dose dependent manner. 3. The effect of sodium fluoride on the osteoblastic cell proliferation was measured by the incorporation of $[^3H]$-thymidine into DNA. As a result, sodium fluoride at $1{\sim}100{\mu}M$ increased the $[^3H]$-thymidine incorporation into DNA in a dose dependent manner. 4. The signaling mechanism activated by sodium fluoride dose-dependently enhanced the tyrosine phosphorylation of the adaptor molecule $Shc^{p66}$ and their association with Grb2, one of earlier events in a MAP kinase activation pathway cascade used by a significant subset of G protein-coupled receptors. 5. The phosphorylation of CREB(cAMP response element binding protein)was inhibited by the sodium fluoride in MC3T3E1 cells. In conclusion, the results of this study suggested that the mitogenic effect of the sodium fluoride in MC3T3E1 cell was stimulated in a dose-dependent manner and suggested "an important role for the interaction between She and Grb2" in controlling the proliferation of osteoblasts.

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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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    • 제24권2호
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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.

Methods for rapid identification of a functional single-chain variable fragment using alkaline phosphatase fusion

  • Lee, Kyung-Woo;Hur, Byung-Ung;Song, Suk-Yoon;Choi, Hyo-Jung;Shin, Sang-Hoon;Cha, Sang-Hoon
    • BMB Reports
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    • 제42권11호
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    • pp.731-736
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    • 2009
  • The generation of functional recombinant antibodies from hybridomas is necessary for antibody engineering. However, this is not easily accomplished due to high levels of aberrant heavy and light chain mRNAs, which require a highly selective technology that has proven complicated and difficult to operate. Herein, we attempt to use an alkaline phosphate (AP)-fused form of single-chain variable fragment (scFv) for the simple identification of a hybridoma-derived, functional recombinant antibody. As a representative example, we cloned the scFv gene from a hybridoma-producing mouse IgG against branched-chain keto acid dehydrogenase complex-E2 (BCKD-E2) into an expression vector containing an in-frame phoA gene. Functional recombinant antibodies were easily identified by conventional enzyme-linked immunosorbent assay (ELISA) by employing scFv-AP fusion protein, which also readily serves as a valuable immuno-detective reagent.

Effect of Prunetin on Streptozotocin-Induced Diabetic Nephropathy in Rats - a Biochemical and Molecular Approach

  • Jose Vinoth Raja Antony Samy;Nirubama Kumar;Sengottuvelu Singaravel;Rajapandiyan Krishnamoorthy;Mohammad A Alshuniaber;Mansour K. Gatasheh;Amalan Venkatesan;Vijayakumar Natesan;Sung-Jin Kim
    • Biomolecules & Therapeutics
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    • 제31권6호
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    • pp.619-628
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    • 2023
  • In the modern era, chronic kidney failure due to diabetes has spread across the globe. Prunetin (PRU), a component of herbal medicines, has a broad variety of pharmacological activities; these may help to slow the onset of diabetic kidney disease. The anti-nephropathic effects of PRU have not yet been reported. The present study explored the potential nephroprotective actions of PRU in diabetic rats. For 28 days, nephropathic rats were given oral doses of PRU (20, 40, and 80 mg/kg). Body weight, blood urea, creatinine, total protein, lipid profile, liver marker enzymes, carbohydrate metabolic enzymes, C-reactive protein, antioxidants, lipid peroxidative indicators, and the expression of insulin receptor substrate 1 (IRS-1) and glucose transporter 2 (GLUT-2) mRNA genes were all examined. Histological examinations of the kidneys, liver, and pancreas were also performed. The oral treatment of PRU drastically lowered the blood glucose, HbA1c, blood urea, creatinine, serum glutamic-oxaloacetic transaminase, serum glutamic pyruvic transaminase, alkaline phosphatase, lipid profile, and hexokinase. Meanwhile, the levels of fructose 1,6-bisphosphatase, glucose-6-phosphatase, and phosphoenol pyruvate carboxykinase were all elevated, but glucose-6-phosphate dehydrogenase dropped significantly. Inflammatory marker antioxidants and lipid peroxidative markers were also less persistent due to this administration. PRU upregulated the IRS-1 and GLUT-2 gene expression in the nephropathic group. The possible renoprotective properties of PRU were validated by histopathology of the liver, kidney, and pancreatic tissues. It is therefore proposed that PRU (80 mg/kg) has considerable renoprotective benefits in diabetic nephropathy in rats.

Modulation of L-type $Ca^{2+}$ Channel Currents by Various Protein Kinase Activators and Inhibitors in Rat Clonal Pituitary $GH_3$ Cell Line

  • Bae, Young-Min;Baek, Hye-Jung;Cho, Ha-Na;Earm, Yung-E;Ho, Won-Kyung
    • The Korean Journal of Physiology and Pharmacology
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    • 제5권2호
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    • pp.139-146
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    • 2001
  • L-type $Ca^{2+}$ channels play an important role in regulating cytosolic $Ca^{2+}$ and thereby regulating hormone secretions in neuroendocrine cells. Since hormone secretions are also regulated by various kinds of protein kinases, we investigated the role of some kinase activators and inhibitors in the regulation of the L-type $Ca^{2+}$ channel currents in rat pituitary $GH_3$ cells using the patch-clamp technique. Phorbol 12,13-dibutyrate (PDBu), a protein kinase C (PKC) activator, and vanadate, a protein tyrosine phosphatase (PTP) inhibitor, increased the $Ba^{2+}$ current through the L-type $Ca^{2+}$ channels. In contrast, bisindolylmaleimide I (BIM I), a PKC inhibitor, and genistein, a protein tyrosine kinase (PTK) inhibitor, suppressed the $Ba^{2+}$ currents. Forskolin, an adenylate cyclase activator, and isobutyl methylxanthine (IBMX), a non-specific phosphodiesterase inhibitor, reduced $Ba^{2+}$ currents. The above results show that the L-type $Ca^{2+}$ channels are activated by PKC and PTK, and inhibited by elevation of cyclic nucleotides such as cAMP. From these results, it is suggested that the regulation of hormone secretion by various kinase activity in $GH_3$ cells may be attributable, at least in part, to their effect on L-type $Ca^{2+}$ channels.

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치수 절단술 약제의 치수 섬유모세포에 대한 세포독성 연구 (THE CYTOTOXICITY OF PULPOTOMY MEDICAMENTS ON HUMAN PULP FIBROBLAST CELLS)

  • 이영희;이긍호
    • 대한소아치과학회지
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    • 제27권1호
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    • pp.151-160
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    • 2000
  • 유치의 치수 절단술에 이용되는 약제들(formaldehyde, formocresol, paraformaldehyde, ferric sulfate)이 농도 변화에 따라 치수 섬유모세포의 활성, 단백질 기질의 합성 및 무기질 침착에 미치는 영향을 규명하고자, 각각 0.01, 0.05, 0.10, 0.25, 0.50, $1.00{\mu}l/ml$의 농도로 사람의 치수 섬유모세포에 24시간 적용시킨 후 세포활성검사와 함께, 조직의 재생과정 중 유기기질이 되는 단백질의 합성능과 무기질 침착에 관여하는 알칼리성 인산효소의 활성에 미치는 영향을 완충액만을 투여한 대조군과 비교 평가한 결과 다음과 같은 결론을 얻었다. 치수 절단술 약제를 첨가한 후 24시간 배양하였을 때, formaldehyde, formocresol, paraformaldehyde등의 경우 약제 농도가 증가함에 따라 대조군에 비하여 치수 섬유모세포의 세포활성이 크게 저하되었으며, ferric sulfate를 이용한 경우에는 세포활성이 유지되거나 약간 촉진되었다. formaldehyde, formocresol, paraformaldehyde사이의 세포활성간에는 유의성 있는 차이가 보여지지 않았다. 치수 절단술 약제 첨가 후 배양액내의 총단백질양에는 큰 변화가 없었으나, paraformaldehyde에 의해 총단백질양이 약간 감소하였다. 약제 첨가 후 세포내의 단백질양을 측정하였을 때, ferric sulfate의 경우, 약제의 농도가 증가하였을 때도 지속적으로 단백질 합성이 저해됨을 알 수 있었다. formaldehyde, formocresol, paraformaldehyde, ferric sulfate는 치수 섬유모세포의 알칼리성 인산효소 활성을 약간 저해하였다.

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