• 제목/요약/키워드: Protein cleavage

검색결과 444건 처리시간 0.022초

Immunohistochemical Study of Steroidogenesis, Proliferation, and Hypoxia-related Proteins in Caprine Corpora Lutea during the Estrous Cycle

  • Chiu, C.H.;Srinivasan, R.;Tseng, T.H.;Chuang, R.F.;Wu, L.S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제22권5호
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    • pp.636-642
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    • 2009
  • The corpus luteum (CL) is a transient endocrine gland that produces progesterone, a product required for the establishment and maintenance of pregnancy. In the absence of pregnancy, the production of progesterone in the CL decreases and the structure itself regresses in size. The life span and function of the CL are regulated by complex interactions between stimulatory (luteotrophic) and inhibitory (luteolytic) mediators. When an ovum is released from a mature follicle, angiogenesis and rapid growth of follicular cells form the CL. The purpose of the present study was to determine whether steroidogenesis, proliferation, and hypoxiarelated proteins are expressed in caprine CL. The expression of proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), and hypoxia-inducible factor $1{\alpha}$ (HIF-$1{\alpha}$) were determined in caprine CL during the estrous cycle. Cytochrome P450 side chain cleavage protein did not vary significantly during the estrous cycle; however, there was an increased expression of $3{\beta}$ -hydroxysteroid dehydrogenase in the early and middle stages, which rapidly decreased in the late stage. The same observations were made with respect to steroidogenic acute regulatory protein. Variations in progesterone content and expression of PCNA, HIF-$1{\alpha}$, and VEGF were consistent with this result. Thus, the steroidogenic proteins, PCNA, HIF-$1{\alpha}$, and VEGF in caprine CL are dependent on the stage of the estrous cycle.

참나무 목초액에 의한 전립선암세포의 apoptosis 유발기전에 관한 연구 (Up-regulation of Bax and Down-regulation of Bcl-2 in Oak Smoke Flavoring(Holyessing)-induced Apoptosis of Human Prostate Carcinoma Cells)

  • 박철;최영현;이원호;최병태;이용태;김경철
    • 동의생리병리학회지
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    • 제17권1호
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    • pp.85-90
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    • 2003
  • We investigated the effects of Oak smoke flavoring (OSF, Holyessing) on the growth of DU145 and PC-3 human prostate carcinoma cells. OSF treatment resulted in a concentration-dependent growth inhibition in both DU145 and PC3 cell lines. The anti-proliferative effect of OSF treatment was associated with the induction of apoptotic cell death which was confirmed by morphological change such as membrane shrinking, rounding up and chromatin condensation in DU145 and PC-3 cells. DNA flow cytometry analysis confirmed that OSF treatment increased population of apoptotic sub-G1 phase. Furthermore, we observed an increase of pro-apoptotic protein Bax expression and a decrease of anti-apoptotic protein Bcl-2 by OSF treatment in a dose-dependent manner. OSF also induced a proteolytic cleavage of specific target proteins such as poly(ADP-ribose) polymerase (PARP) and β-catenin proteins. The present results indicated that OSF-induced inhibition of human prostate carcinoma cell proliferation is associated with the induction of apoptosis.

Crystallization and X-Ray Crystallographic Studies of Wild-Type and Mutant Tryptophan Synthase α-Subunits from Escherichia coli

  • Jeong, Mi Suk;Jang, Se Bok
    • Molecules and Cells
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    • 제19권2호
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    • pp.219-222
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    • 2005
  • The a-subunit of Escherichia coli tryptophan synthase (${\alpha}TS$), a component of the tryptophan synthase ${\alpha}_2{\beta}_2$ complex, is a monomeric 268-residues protein (Mr = 28,600). ${\alpha}TS$ by itself catalyzes the cleavage of indole-3-glycerol phosphate to glyceraldehyde-3-phosphate and indole, which is converted to tryptophan in tryptophan biosynthesis. Wild-type and P28L/Y173F double mutant ${\alpha}$-subunits were overexpressed in E. coli and crystallized at 298 K by the hanging-drop vapor-diffusion method. X-ray diffraction data were collected to $2.5{\AA}$ resolution from the wild-type crystals and to $1.8{\AA}$ from the crystals of the double mutant, since the latter produced better quality diffraction data. The wild-type crystals belonged to the monoclinic space group C2 ($a=155.64{\AA}$, $b=44.54{\AA}$, $c=71.53{\AA}$ and ${\beta}=96.39^{\circ}$) and the P28L/Y173F crystals to the monoclinic space group $P2_1$ ($a=71.09{\AA}$, b=52.70, $c=71.52{\AA}$ and ${\beta}=91.49^{\circ}$). The asymmetric unit of both structures contained two molecules of ${\alpha}TS$. Crystal volume per protein mass ($V_m$) and solvent content were $2.15{\AA}^3\;Da^{-1}$ and 42.95% for the wild-type and $2.34{\AA}^3\;Da^{-1}$ and 47.52% for the double mutant.

백작약 추출물의 전립선 암세포 고사 유도 효과 및 기전 연구 (Study on Apoptosis-Inducing Effects and Mechanism of Radix Paeoniae Alba Extract in DU145 Human Prostate Cancer Cell)

  • 권강범;김은경;김경종;강길성;김영선;김인규;김인섭;김인수;이수경;서은아;류도곤
    • 동의생리병리학회지
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    • 제18권6호
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    • pp.1617-1621
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    • 2004
  • The aim of this study was to investigate the apoptotic effect and its mechanism on Radix Paeoniae Alba Extract(RPAE) in DU145 human prostate cancer cell line. RPAE induced apoptosis in a dose-dependent manner in DU145 cells as confirmed by both discontinuous DNA fragmentation using Hoechst33342 staining and poly-(ADP-ribose) polymerase(PARP) cleavage, which are apoptotic signs. To clarify the mechanisms on RPAE-induced apoptosis, we examined the p50(NF-κB subunit), IκBα, PTEN and Par-4 protein expression using Western blotting. Treatment with RPAE resulted in the decrease of p50 expression by IκBα increase, which resulted in Par-4 increase and bcl-2 decrease in DU145 cells. These results suggest that apoptosis of DU145 cells by RPAE involved decreases of NF-κB activation and bcl-2 expression, increase of Par-4 protein expression.

애엽(艾葉)의 미토콘드리아 보호 효과 (Cytoprotective Effects of Artemisia princeps Extract through Inhibition of Mitochondrial Dysfunction)

  • 최희윤;제갈경환;김영우;이정우;조수아;조일제;김상찬
    • 대한한의학방제학회지
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    • 제21권2호
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    • pp.63-71
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    • 2013
  • Objectives : Artemisia princeps is used as moxa in moxibustion and traditional herbal medicine. And its extracts or compounds is known to have an efficacy of antioxidant, anti-diabete, anti-cancer, anti-inflammation and neuroprotection. This study was performed to investigate the cytoprotective effect of Artemisia princeps extract (APE) against arachidonic acid (AA)+iron-induced oxidative stress on HepG2 cell. Methods : The effects of APE on cell viability has been assessed using MTT assay. And flow cytometric analysis was performed to estimate APE's effects on mitochondrial function. To investigate its underlying mechanism, related protein was analysed by using immunoblot analysis. Results : Treatment of APE increased relative cell viability, prevented a decline of B-cell lymphoma-extra large (Bcl-xL) and cleavage of poly(ADP-ribose) polymerase (PARP) and procaspase-3, and also protected mitochondrial membrane permeability (MMP) against oxidative stress induced by AA+iron. In addition, APE treatment increased phosphorylation of AMP-activated protein kinase (AMPK) exerts a cytoprotective effect. Conclusions : This results demonstrate that APE has an ability to activation of AMPK which protects cells from AA+iron-induced oxidative stress and restores MMP.

A New Neolignan Derivative, Balanophonin Isolated from Firmiana simplex Delays the Progress of Neuronal Cell Death by Inhibiting Microglial Activation

  • Lim, Soo Young;Subedi, Lalita;Shin, Dongyun;Kim, Chung Sub;Lee, Kang Ro;Kim, Sun Yeou
    • Biomolecules & Therapeutics
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    • 제25권5호
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    • pp.519-527
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    • 2017
  • Excessive activation of microglia causes the continuous production of neurotoxic mediators, which further causes neuron degeneration. Therefore, inhibition of microglial activation is a possible target for the treatment of neurodegenerative disorders. Balanophonin, a natural neolignoid from Firmiana simplex, has been reported to have anti-inflammatory and anti-cancer effects. In this study, we aimed to evaluate the anti-neuroinflammatory effects and mechanism of balanophonin in lipopolysaccharide (LPS)-stimulated BV2 microglia cells. BV2 microglia cells were stimulated with LPS in the presence or absence of balanophonin. The results indicated that balanophonin reduced not only the LPS-mediated TLR4 activation but also the production of inflammatory mediators, such as nitric oxide (NO), prostaglandin E2 (PGE2), $Interleukin-1{\beta}$ ($IL-1{\beta}$), and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), in BV2 cells. Balanophonin also inhibited LPS-induced inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX2) protein expression and mitogen activated protein kinases (MAPKs), including extracellular signal-regulated kinase (ERK1/2), c-Jun N-terminal kinase (JNK), and p38 MAPK. Interestingly, it also inhibited neuronal cell death resulting from LPS-activated microglia by regulating cleaved caspase-3 and poly ADP ribose polymerase (PARP) cleavage in N2a cells. In conclusion, our data indicated that balanophonin may delay the progression of neuronal cell death by inhibiting microglial activation.

인체 전립선 암세포에서 Alkylating Agent인 N-methyl-N'-nitro- N-nitrosoguanidine에 의한 Apoptosis유발 (Induction of Apoptosis by N-methyl-N'-nitro-N-nitrosoguanidine, an Alkylating Agent, in Human Prostate Carcinoma Cells)

  • 박철;최병태;이원호;최영현
    • Toxicological Research
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    • 제19권2호
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    • pp.91-98
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    • 2003
  • Alkylating agents form alkylated base adducts in the DNA and cause DNA lesions leading to cell killing. In this study, we investigated the mechanism of apoptosis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in PC-3 and DU145 human prostate carcinoma cell lines. MNNG treatment resulted in the inhibition of cell proliferation in a concentration-dependent manner to a similar extent in both cell lines. This anti-proliferative effect of PC-3 and DU145 cells by MNNG was associated with morphological changed such as membrane shrinking, cell rounding up and formation of apoptotic bodies. MNNG treatment also induced a proteolytic cleavage of specific target proteins such as poly(ADP-ribose) polymerase (PARP) and $\beta$-catenin proteins in DU145 cells but in PC-3 cells. Furthermore, we observed an increase of proapoptotic protein Bax family expression and a decrease of antiapoptotic protein Bcl-2 family by MNNG treatment in a concentration-dependent manner MNNG also induced a proteolytic activation of caspase-3 and -9, which is believed to play a central role in the apoptotic signaling pathway.

Curcumin Induces Downregulation of E2F4 Expression and Apoptotic Cell Death in H CT116 Human Colon Cancer Cells; Involvement of Reactive Oxygen Species

  • Kim, Kyung-Chan;Lee, Chu-Hee
    • The Korean Journal of Physiology and Pharmacology
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    • 제14권6호
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    • pp.391-397
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    • 2010
  • E2F transcription factors and their target genes have been known to play an important role in cell growth control. We found that curcumin, a polyphenolic phytochemical isolated from the plant Curcuma longa, markedly suppressed E2F4 expression in HCT116 colon cancer cells. Hydrogen peroxide was also found to decrease E2F4 protein level, indicating the involvement of reactive oxygen species (ROS) in curucmin-induced downregulation of E2F4 expression. Involvement of ROS in E2F4 downregulation in response to curcumin was confirmed by the result that pretreatment of cells with N-acetylcystein (NAC) before exposure of curcumin almost completely blocked the reduction of E2F4 expression at the protein as well as mRNA level. Anti-proliferative effect of curcumin was also suppressed by NAC which is consistent to previous reports showing curcumin-superoxide production and induction of poly (ADP-ribose) polymerase (PARP) cleavage as well as apoptosis. Expression of several genes, cyclin A, p21, and p27, which has been shown to be regulated in E2F4-dependent manner and involved in the cell cycle progression was also affected by curcumin. Moreover, decreased (cyclin A) and increased (p21 and p27) expression of these E2F4 downstream genes by curcumin was restored by pretreatment of cells with NAC and E2F4 overexpression which is induced by doxycycline. In addition, E2F4 overexpression was observed to partially ameliorate curcumin-induced growth inhibition by cell viability assay. Taken together, we found curcumin-induced ROS down-regulation of E2F4 expression and modulation of E2F4 target genes which finally lead to the apoptotic cell death in HCT116 colon cancer cells, suggesting that E2F4 appears to be a novel determinant of curcumin-induced cytotoxicity.

H9 Induces Apoptosis via the Intrinsic Pathway in Non-Small-Cell Lung Cancer A549 Cells

  • Kwon, Sae-Bom;Kim, Min-Je;Sun Young, Ham;Park, Ga Wan;Choi, Kang-Duk;Jung, Seung Hyun;Do-Young, Yoon
    • Journal of Microbiology and Biotechnology
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    • 제25권3호
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    • pp.343-352
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    • 2015
  • H9 is an ethanol extract prepared from nine traditional/medicinal herbs. This study was focused on the anticancer effect of H9 in non-small-cell lung cancer cells. The effects of H9 on cell viability, apoptosis, mitochondrial membrane potential (MMP; ${\Delta}\psi_{m}$), and apoptosisrelated protein expression were investigated in A549 human lung cancer cells. In this study, H9-induced apoptosis was confirmed by propidium iodide staining, expression levels of mRNA were determined by reverse transcriptase polymerase chain reaction, protein expression levels were checked by western blot analysis, and MMP (${\Delta}\psi_{m}$) was measured by JC-1 staining. Our results indicated that H9 decreased the viability of A549 cells and induced cell morphological changes in a dose-dependent manner. H9 also altered expression levels of molecules involved in the intrinsic signaling pathway. H9 inhibited Bcl-xL expression, whereas Bax expression was enhanced and cytochrome C was released. Furthermore, H9 treatment led to the activation of caspase-3/caspase-9 and proteolytic cleavage of poly(ADP-ribose) polymerase; the MMP was collapsed by H9. However, the expression levels of extrinsic pathway molecules such as Fas/FasL, TRAIL/TRAIL-R, DR5, and Fas-associated death receptor were downregulated by H9. These results indicated that H9 inhibited proliferation and induced apoptosis by activating intrinsic pathways but not extrinsic pathways in human lung cancer cells. Our results suggest that H9 can be used as an alternative remedy for human non-small-cell lung cancer.

Antiproliferative and Cytotoxic Effects of Resveratrol in Mitochondria-Mediated Apoptosis in Rat B103 Neuroblastoma Cells

  • Rahman, Md. Ataur;Kim, Nam-Ho;Kim, Seung-Hyuk;Oh, Sung-Min;Huh, Sung-Oh
    • The Korean Journal of Physiology and Pharmacology
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    • 제16권5호
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    • pp.321-326
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    • 2012
  • Resveratrol, a natural compound, has been shown to possess anti-cancer, anti-aging, anti-inflammatory, anti-microbial, and neuroprotective activities. In this study, we examined the antiproliferative and cytotoxicity properties of resveratrol in Rat B103 neuroblastoma cells; although it's molecular mechanisms for the biological effects are not fully defined. Here, we examined the cellular cytotoxicity of resveratrol by cell viability assay, antiproliferation by BrdU assay, DNA fragmentation by DNA ladder assay, activation of caspases and Bcl-2 family proteins were detected by western blot analyses. The results of our investigation suggest that resveratrol increased cellular cytotoxicity of Rat B103 neuroblastoma cells in a dose-and time-dependent manner with $IC_{50}$ of 17.86 ${\mu}M$ at 48 h. On the other hand, incubation of neuroblastoma cells with resveratrol resulted in S-phase cell cycle arrests which dose-dependently and significantly reduced BrdU positive cells through the downregulation of cyclin D1 protein. In addition, resveratrol dose-dependently and significantly downregulated the expression of anti-apoptotic protein includes Bcl-2, Bcl-xL and Mcl-1 and also activates cleavage caspase-9 and-3 via the downregulation of procaspase-9 and -3 in a dose-dependent manner which indicates that involvement of intrinsic mitochondria-mediated apoptotic pathway. In conclusion, resveratrol increases cellular cytotoxicity and inhibits the proliferation of B103 neuroblastoma cells by inducing mitochondria-mediated intrinsic caspase dependent pathway which suggests this natural compound could be used as therapeutic purposes for neuroblastoma malignancies.