• Title/Summary/Keyword: {\alpha}$

Search Result 24,684, Processing Time 0.05 seconds

Role of p38 MAPK in the Regulation of Apoptosis Signaling Induced by TNF-α in Differentiated PC12 Cells

  • Park, Jung-Gyu;Yuk, Youn-Jung;Rhim, Hye-When;Yi, Seh-Yoon;Yoo, Young-Sook
    • BMB Reports
    • /
    • v.35 no.3
    • /
    • pp.267-272
    • /
    • 2002
  • TNF-$\alpha$ elicits various responses including apoptosis, proliferation, and differentiation according to cell type. In neuronal PC12 cells, TNF-$\alpha$ induces moderate apoptosis while lipopolysarccaharide or trophic factor deprivation can potentiate apoptosis that is induced by TNF-$\alpha$. TNF-$\alpha$ initiates various signal transduction pathways leading to the activation of the caspase family, NF-${\kappa}B$, Jun N-terminal kinase, and p38 MAPK via the death domain that contains the TNF-$\alpha$ receptor. Inhibition of translation using cycloheximide greatly enhanced the apoptotic effect of TNF-$\alpha$. This implies that the induction of anti-apoptotic genes for survival by TNF-$\alpha$ may be able to protect PC12 cells from apoptosis. Accordingly, Bcl-2, an anti-apoptotic genes for survival by TNF-$\alpha$ may be able to protect PC12 cells from apoptosis. Accordingly, Bcl-2, an anti-apoptotic Bcl-2 family member, was highly expressed in response to TNF-$\alpha$. In this study, we examined the anti-apoptotic role of p38 MAPK that is activated by TNF-$\alpha$ in neuronal PC12 cells. The phosphorylation of p38 MAPK in response to TNF-$\alpha$ slowly increased and lasted several hours in the PC12 cell and DRG neuron. This specific inhibitor of p38 MAPK, SB202190, significantly enhanced the apoptosis that was induced by TNF-$\alpha$ in PC12 cells. This indicates that the activation of p38 MAPK could protect PC12 cells from apoptosis since there is no known role of p38 MAPK in resoonse to TNF-$\alpha$ in neuron. This discovery could be evidence for the neuroprotective role of the p38 MAPK.

Synthesis of Glycosides by Transglycosylation of $\alpha$-Amylase from Soluble Starch in Water-Organic Two Phase System (전분을 기질로 한 이상계에서 Amylase의 당전이반응에 의한 배당체의 합성)

  • 박종이;이재동;이태호;장경립
    • Korean Journal of Microbiology
    • /
    • v.35 no.1
    • /
    • pp.1-6
    • /
    • 1999
  • Benzylalcohol-$\alpha$-glucoside (BG) was synthesized from soluble starch by transglycosylation of $\alpha$-amylase. Transglycosylation in water-organic two phase system containing 1% soluble starch as a glycosyl donor, 90% benzylalcohol as a glycosyl acceplor, 10% citrate buffer solulion (0.1 M, pH 5.0), and 10 unit of $\alpha$-amylase (Aspergilllw oryzae) was showed highcst efficiency. About 4 mg BG was obtained from 10 mg starch in reaction for 80 hrs at $40^{\circ}C$. Initially benzylalcohol-$\alpha$-maltoside Q3M) was major product, but as the reaction proceeded, it was hydrolyzed to glucose and BG. Finally the product of transglycosylation by $\alpha$-amylase was only BG. The both products did not show reducing powcr and hydrolyzed by $\alpha$-glucosidase and $\alpha$-amylase, respectively. The molecular wcights of both were estimated to be 270 and 432 by ES1-Mass, respectively.

  • PDF

Ameliorating Effects of Atractylodes macrocephala Koidzumi on TNF-α-induced 3T3-L1 Adipocyte Dysfunction (백출추출물이 TNF-α 유도 지방세포염증과 인슐린저항성 회복에 미치는 영향)

  • Bin, Chang-Hyun;Song, Choon-Ho
    • Korean Journal of Acupuncture
    • /
    • v.32 no.3
    • /
    • pp.116-123
    • /
    • 2015
  • Objectives : The present study was designed to investigate effects and molecular mechanisms of Atractylodes macrocephala Koidzumi extracts(AMK) on the improvement of adipocyte dysfunction induced by TNF-${\alpha}$ in 3T3-L1 adipocytes. We examined whether AMK could directly influence the inflammation and insulin resistance in 3T3-L1 adipocytes. Methods : Potential roles of AMK in the lipolysis, production of inflammatory adipokines and ROS, expression and phosphorylation of ERK, JNK, and $I{\kappa}B{\alpha}$ protein, and expression of $PPAR{\gamma}$ and C/EBP${\alpha}$ were investigated in this study. Results : Our data demonstrated that TNF-${\alpha}$ significantly increased lipolysis, levels of MCP-1, IL-6, and ROS and phosphorylation of ERK, JNK, and $I{\kappa}B{\alpha}$ protein, while TNF-${\alpha}$ reduced the expression of $PPAR{\gamma}$ and C/EBP${\alpha}$ in adipocytes, suggesting that TNF-${\alpha}$ induced a condition with the occurrence of inflammation and insulin resistance. Those alterations induced by TNF-${\alpha}$ were prevented by the treatment of AMK. AMK down-regulated the phosphorylation of ERK, JNK, and $I{\kappa}B{\alpha}$ protein and up-regulated the expression of $PPAR{\gamma}$ and C/EBP${\alpha}$ on TNF-${\alpha}$-induced inflammation and insulin resistance. Conclusions : Thus, our results indicate that AMK can be used to prevent from the TNF-${\alpha}$-induced adipocyte dysfunction through MAPK, $NF{\kappa}B$ and $PPAR{\gamma}$ pathways.

Mechanical Properties of Partially Stabilized $\alpha$-Sialon Synthesized from Kimcheon Quartzite (김천규석으로부터 제조한 부분안정화 $\alpha$-Sialon의 기계적 물성)

  • 서원선;조덕호;이홍림
    • Journal of the Korean Ceramic Society
    • /
    • v.25 no.2
    • /
    • pp.143-153
    • /
    • 1988
  • In order to synthesize the partially stabilized $\alpha$-Sialon, A1N and Y2O3 were added to synthesized $\alpha$-Si3N4. The phase composition, mechanical properties, micro structure, etc, of the synthesized $\alpha$-Sialon were investigated. Partially stabilized $\alpha$-Sialon ceramics could be synthesized from the composition which was a little deviated from x=0.4, x=0.6 composition along the Si3N4.0.1Y2O3:0.9AlN tie line at 1750-180$0^{\circ}C$ for 2 hrs in N2 atmosphere. It is assumed that A1N is more closely related than Y2O3 to the formation of $\alpha$-Sialon, and that A1N is more easily dissolved into $\alpha$-structure than into $\beta$-structure. In Ya2O3-rich phase mechanical properties were observed to be poor because of formation of mellilite, grain growth, and thermal decomposition of $\alpha$-Sialon. The maximum values of M.O.R, KIC and hardness are 723 MPa, 4.5MN/㎥/2 and 19.3 GPa, respectively, and they were observed for the $\alpha$-Sialon ceramics sintered at 178$0^{\circ}C$.

  • PDF

Differential Coupling of G$\alpha$q Family of G-protein to Muscarinic $M_1$ Receptor and Neurokinin-2-Receptor

  • Lee, Chang-Ho;Shin, In-Chul;Kang, Ju-Seop;Koh, Hyun-Chul;Ha, Ji-Hee;Min, Chul-Ki
    • Archives of Pharmacal Research
    • /
    • v.21 no.4
    • /
    • pp.423-428
    • /
    • 1998
  • The ligand binding signals to a wide variety of seven transmembrane cell surface receptors are transduced into intracellular signals through heterotrimeric G-proteins. Recently, there have been reports which show diverse coupling patterns of ligand-activated receptors to the members of Gq family $\alpha$ subunits. In order to shed some light on these complex signal processing networks, interactions between G$\alpha$q family of G protein and neurokinin-2 receptor as well as muscarinic M$_{1}$ receptor, which are considered to be new thearpeutic targets in asthma, were studied. Using washed membranes from Cos-7 cells co-transfected with different G.alpha.q and receptor cDNAs, the receptors were stimulated with various concentrations of carbachol and neurokinin A and the agonist-dependent release of [$^3H$]inositol phosphates through phospholipase C beta-1 activation was measured. Differential coupling of Gaq family of G-protein to muscarinic M$_{1}$ receptor and neurokinin-2 receptor was observed. The neurokinin-2 receptor shows a ligand-mediated response in membranes co-transfected with G$\alpha$q, G$\alpha$11 and G$\alpha$14 but not G$\alpha$16 and the ability of the muscarinic $M_1$ receptor to activate phospholipase C through G$\alpha$/11 but not G$\alpha$14 and G$\alpha$16 was demonstrated. Clearly G$\alpha$/11 can couple $\M_1$ and neurokinin-2 receptor to activate phospholipase C. But, there are differences in the relative coupling of the G$\alpha$14 and G$\alpha$16 subunits to these receptors.

  • PDF

Effect of Ramaria botrytis Methanol Extract on Antioxidant Enzyme Activities in $Benzo({\alpha})Pyrene-treated$ Mice (싸리버섯 메탄올 추출물이 벤조피렌을 투여한 마우스의 항산화 효소 활성에 미치는 영향)

  • Kim, Hyun-Jeong;Lee, Kap-Rang
    • Korean Journal of Food Science and Technology
    • /
    • v.35 no.2
    • /
    • pp.286-290
    • /
    • 2003
  • Effects of Ramaria botrytis methanol extract on hepatotoxicity in $benzo({\alpha})pyrene(B({\alpha})P)-treated$ mice were investigated. R. botrytis methanol extract was intraperitioneally injected once a day for successive 5 days, followed by treatment with $B({\alpha})P$ on the fifth day. Antioxidant activities of R. botrytis methanol extract were examined by measuring the free radical-scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. In DPPH method, R. botrytis methanol extract showed strong antioxidative activies. The increased activities of superoxide dismutase, catalase, and glutathione peroxidase after $B({\alpha})P-treatment$ were decreased by treatment of R. botrytis methanol extract. Glutathione content and glutathione S-transferase activity depleted by $B({\alpha})P$ were significantly increased, but elevation of lipid peroxide content induced by $B({\alpha})P$ was decreased by R. botrytis methanol extract. These results suggest that R. botrytis methanol extract is believe to be a possible protective effect against $B(\alpha)P-induced$ hepatotoxicity in mice.

Isolation and Identification of Inhibitory Compound from Crataegi Fructus on ${\alpha}-amylase$ and ${\alpha}-glucosidase$ (산사(Crataegi Fructus) 추출물로부터 ${\alpha}-amylase$${\alpha}-glucosidase$ 저해 물질 분리 및 동정)

  • Kim, Myung-Uk;Cho, Young-Je;Kim, Jeung-Hoan
    • Applied Biological Chemistry
    • /
    • v.50 no.3
    • /
    • pp.204-209
    • /
    • 2007
  • The objective of this research was to evaluate the inhibitory activities of phenolic compounds isolated from Crataegi Fructus on ${\alpha}-amylase$ and ${\alpha}-glucosidase$. The content of total phenolic compounds of water extract from Crataegi Fructus was 22.5 mg/g. The inhibitory activity of the water extract (200 ${\mu}g/ml$) from Crataegi Fructus on ${\alpha}-amylase$ and ${\alpha}-glucosidase$ was determined to be 100% and 82.6%, respectively. Isolation of inhibitory compounds was carried out on Sephadex LH-20 and MCI-gel CHP-20 column chromatography using a gradient elution procedure of increasing MeOH in $H_2O$. The chemical structure of the inhibitory compound against ${\alpha}-amylase$ and ${\alpha}-glucosidase$ was confirmed as chlorogenic acid by spectroscopic analysis of FAB-MS, NMR and IR spectrum.

Tumor Necrosis Factor-Alpha $(TNF-{\alpha})$ Induces PTEN Expression in HL-60 Cells (백혈병세포에서 종양괴사인자에 의한 PTEN 발현증가)

  • Lee Seung-Ho;Park Chul-Hong;Kim Byeong-Su
    • Journal of Food Hygiene and Safety
    • /
    • v.21 no.3
    • /
    • pp.181-188
    • /
    • 2006
  • Tumor necrosis factor-alpha $(TNF-{\alpha})$ plays a variety of biological functions such as apoptosis, inflammation and immunity. PTEN also has various cellular function including cell growth, proliferation, migration and differentiation. Thus, possible relationships between two molecules are suggested. $(TNF-{\alpha})$has been known to downregulate PTEN via nuclear factor-kappa $B(NF-{\kappa}B)$ pathway in the human colon cell line, HT-29. However, here we show the opposite finding that $(TNF-{\alpha})$ upregulates PTEN via activation of $NF-{\kappa}B$ in HL-60 cells. $TNF-{\alpha}$ increased PTEN expression at HL-60 cells in a time- and dose-dependent manner, but the response was abolished by disruption of $NF-{\kappa}B$ with p65 anisense oligonucleotide or pyrrolidine dithiocarbamate (PDTC). We found that $TNF-{\alpha}$ activated the $NF-{\kappa}B$ pathways, evidenced by the translocation of p65 to the nucleus in $TNF-{\alpha}-treated$ cells. We conclude that $TNF-{\alpha}$ induces upregulation of PTEN expression through $NF-{\kappa}B$ activation in HL-60 cells.

Changes of the Structural and Biomechanical Properties of the Bovine Pericardium after the Removal of ${\alpha}$-Gal Epitopes by Decellularization and ${\alpha}$-Galactosidase Treatment

  • Nam, Jinhae;Choi, Sun-Young;Sung, Si-Chan;Lim, Hong-Gook;Park, Seong-Sik;Kim, Soo-Hwan;Kim, Yong Jin
    • Journal of Chest Surgery
    • /
    • v.45 no.6
    • /
    • pp.380-389
    • /
    • 2012
  • Background: Bovine pericardium is one of the most widely used materials in bioprosthetic heart valves. Immunologic responses have been implicated as potential causes of limited durability of xenogenic valves. This study aimed to determine the effectiveness of decellularization and ${\alpha}$-galactosidase (${\alpha}$-gal) to remove major xenoreactive antigens from xenogenic tissues. Materials and Methods: Recombinant Bacteroides thetaiotaomicron (B. thetaiotaomicron) ${\alpha}$-gal or decellularization, or both were used to remove ${\alpha}$-gal from bovine pericardium. It was confirmed by ${\alpha}$-gal-bovine serum albumin-based enzyme-linked immunosorbent assay (ELISA), high-performance anion exchange chromatography, flow cytometry, 3,3'-diaminobenzidine-staining, and lectin-based ELISA. The mechanical properties of bovine pericardium after decellularization or ${\alpha}$-gal treatment were investigated by tests of tensile-strength, permeability, and compliance. Collagen fiber rearrangement was also evaluated by a 20,000${\times}$ transmission electron microscope (TEM). Results: Recombinant B. thetaiotaomicron ${\alpha}$-gal could effectively remove ${\alpha}$-gal from bovine pericardium B. thetaiotaomicron (0.1 U/mL, pH 7.2) while recombinant human ${\alpha}$-gal removed it recombinant human ${\alpha}$-gal (10 U/mL, pH 5.0). There was no difference in the mechanical properties of fresh and recombinant ${\alpha}$-gal-treated bovine pericardium. Furthermore, the TEM findings demonstrated that recombinant ${\alpha}$-gal made no difference in the arrangement of collagen fiber bundles with decellularization. Conclusion: Recombinant B. thetaiotaomicron ${\alpha}$-gal effectively removed ${\alpha}$-gal from bovine pericardium with a small amount under physiological conditions compared to human recombinant ${\alpha}$-gal, which may alleviate the harmful xenoreactive immunologic responses of ${\alpha}$-gal. Recombinant ${\alpha}$-gal treatment had no adverse effects on the mechanical properties of bovine pericardium.

Studies on Milk Protein by Zone Electrophoresis (대전기영동법(帶電氣泳動法)에 의한 유청단백질(乳淸蛋白質)에 관(關)한 연구(硏究))

  • Cho, Duk-Bong;Nam, Hyun-Keun
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.5 no.1
    • /
    • pp.25-30
    • /
    • 1976
  • In this investigation, the physico-chemical properties of Korean cattles milk and Holstein cows milk are studied. The results of the milk -protein of F-1, F-2, and F-4 hybrid are interested in this studied. 1. The physico-chemical properties of Korean cattle and Holstein cows milk is summarized at Table 1, Table 2. 2. The electrophoretic milk protein fraction of Korean cattle is identified : Lactoalbumin 1.74mg%. Alpha-1 globulin 1.19mg%, Alpha-2 globulin 0.68mg%, Beta-globulin 2.57mg%, Gamma-globulin 0.93mg%. 3. The electrophoretic milk protein fraction of Holstein cow : Lactoalbumin 1.23mg%, Alpha-1 globulin 0.93mg%, Alpha-2 globulin 0.86mg%, Bata-globulin 2.56mg%, Gamma-globulin 1.74mg% have been identified. 4. The electrophoretic milk protein fraction of hybrid F-1, F-2, and F-4 between Korean cattle(female) and Holstein(male) is obtained the following : F-1 hybrid : Lactoalbumin 1.38mg%, Alpha-1 globulin 1.58mg%, Alpa-2 globulin 2.46mg%, Beta-globulin 1.39mg%. F-2 hybrid : Lactoalbumin 1.57mg%, Alpha-1 globulin 1.74mg%, Alpha-2 globulin 2.19mg%, Beta-globulin 1.74mg%. F-4 hybrid : Lactoalbumin 2.46mg%, Alpha-1 globulin 1. 24mg%, Alpha-2 globulin 1.57㎎%, Beta-globulin 1.74mg%.

  • PDF