• 제목/요약/키워드: Extrinsic pathway

검색결과 77건 처리시간 0.032초

Induction of Intrinsic and Extrinsic Apoptosis Pathways in the Human Leukemic MOLT-4 Cell Line by Terpinen-4-ol

  • Khaw-On, Patompong;Banjerdpongchai, Ratana
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권7호
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    • pp.3073-3076
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    • 2012
  • Terpinen-4-ol is a terpene found in the rhizome of Plai (Zingiber montanum (Koenig) Link ex Dietr.). In this study apoptogenic activity and mechanisms of cell death induced by terpinen-4-ol were investigated in the human leukemic MOLT-4 cell line. Terpinen-4-ol exhibited cytotoxicity in MOLT-4 cells, with characteristic morphological features of apoptosis by Wright's staining. The mode of cell death was confirmed to be apoptosis by flow cytometric analysis after staining with annexin V-FITC and propidium iodide. A sub-G1 peak in DNA histograms of cell cycle assays was observed. Terpinen-4-ol induced-MOLT-4 cell apoptosis mediated through an intrinsic pathway involving the loss of mitochondrial transmembrane potential (MTP) and release of cytochrome c into the cytosol. In addition, terpinen-4-ol also induced apoptosis via an extrinsic pathway by caspase-8 activation resulting in the cleavage of cytosolic Bid. Truncated-Bid (tBid) translocated to mitochondria and activated the mitochondrial pathway in conjunction with down-regulation of Bcl-2 protein expression. Caspase-3 activity also increased. In conclusion, terpinen-4-ol can induce human leukemic MOLT-4 cell apoptosis via both intrinsic and extrinsic pathways.

E3 ubiquitin ligases and deubiquitinases as modulators of TRAIL-mediated extrinsic apoptotic signaling pathway

  • Woo, Seon Min;Kwon, Taeg Kyu
    • BMB Reports
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    • 제52권2호
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    • pp.119-126
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    • 2019
  • The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) initiates the extrinsic apoptotic pathway through formation of the death-inducing signaling complex (DISC), followed by activation of effector caspases. TRAIL receptors are composed of death receptors (DR4 and DR5), decoy receptors (DcR1 and DcR2), and osteoprotegerin. Among them, only DRs activate apoptotic signaling by TRAIL. Since the levels of DR expressions are higher in cancer cells than in normal cells, TRAIL selectively activates apoptotic signaling pathway in cancer cells. However, multiple mechanisms, including down-regulation of DR expression and pro-apoptotic proteins, and up-regulation of anti-apoptotic proteins, make cancer cells TRAIL-resistant. Therefore, many researchers have investigated strategies to overcome TRAIL resistance. In this review, we focus on protein regulation in relation to extrinsic apoptotic signaling pathways via ubiquitination. The ubiquitin proteasome system (UPS) is an important process in control of protein degradation and stabilization, and regulates proliferation and apoptosis in cancer cells. The level of ubiquitination of proteins is determined by the balance of E3 ubiquitin ligases and deubiquitinases (DUBs), which determine protein stability. Regulation of the UPS may be an attractive target for enhancement of TRAIL-induced apoptosis. Our review provides insight to increasing sensitivity to TRAIL-mediated apoptosis through control of post-translational protein expression.

The Heat Shock Protein 27 (Hsp27) Operates Predominantly by Blocking the Mitochondrial-Independent/Extrinsic Pathway of Cellular Apoptosis

  • Tan, Cheau Yih;Ban, Hongseok;Kim, Young-Hee;Lee, Sang-Kyung
    • Molecules and Cells
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    • 제27권5호
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    • pp.533-538
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    • 2009
  • Heat shock protein 27 (Hsp27) is a molecular chaperone protein which regulates cell apoptosis by interacting directly with the caspase activation components in the apoptotic pathways. With the assistance of the Tat protein transduction domain we directly delivered the Hsp27 into the myocardial cell line, H9c2 and demonstrate that this protein can reverse hypoxia-induced apoptosis of cells. In order to characterize the contribution of Hsp27 in blocking the two major apoptotic pathways operational within cells, we exposed H9c2 cells to staurosporine and cobalt chloride, agents that induce mitochondria-dependent (intrinsic) and -independent (extrinsic) pathways of apoptosis in cells respectively. The Tat-Hsp27 fusion protein showed a greater propensity to inhibit the effect induced by the cobalt chloride treatment. These data suggest that the Hsp27 predominantly exerts its protective effect by interfering with the components of the extrinsic pathway of apoptosis.

Arctigenin induces caspase-dependent apoptosis in FaDu human pharyngeal carcinoma cells

  • Kang, Kyeong-Rok;Kim, Jae-Sung;Lim, HyangI;Seo, Jeong-Yeon;Park, Jong-Hyun;Chun, Hong Sung;Yu, Sun-Kyoung;Kim, Heung-Joong;Kim, Chun Sung;Kim, Do Kyung
    • The Korean Journal of Physiology and Pharmacology
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    • 제26권6호
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    • pp.447-456
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    • 2022
  • The present study was carried out to investigate the effect of Arctigenin on cell growth and the mechanism of cell death elicited by Arctigenin were examined in FaDu human pharyngeal carcinoma cells. To determine the apoptotic activity of Arctigenin in FaDu human pharyngeal carcinoma cells, cell viability assay, DAPI staining, caspase activation analysis, and immunoblotting were performed. Arctigenin inhibited the growth of cells in a dose-dependent manner and induced nuclear condensation and fragmentation. Arctigenin-treated cells showed caspase-3/7 activation and increased apoptosis versus control cells. FasL, a death ligand associated with extrinsic apoptotic signaling pathways, was up-regulated by Arctigenin treatment. Moreover, caspase-8, a part of the extrinsic apoptotic pathway, was activated by Arctigenin treatments. Expressions of anti-apoptotic factors such as Bcl-2 and Bcl-xL, components of the mitochondria-dependent intrinsic apoptosis pathway, significantly decreased following Arctigenin treatment. The expressions of pro-apoptotic factors such as BAX, BAD and caspase-9, and tumor suppressor -53 increased by Arctigenin treatments. In addition, Arctigenin activated caspase-3 and poly (ADP-ribose) polymerase (PARP) induced cell death. Arctigenin also inhibited the proliferation of FaDu cells by the suppression of p38, NF-κB, and Akt signaling pathways. These results suggest that Arctigenin may inhibit cell proliferation and induce apoptotic cell death in FaDu human pharyngeal carcinoma cells through both the mitochondria-mediated intrinsic pathway and the death receptor-mediated extrinsic pathway.

Apoptosis의 외인성 경로에서 caspase-8의 구조적 및 기능적 역할 (Structural and Functional Roles of Caspase-8 in Extrinsic Apoptosis)

  • 하민선;정미숙;장세복
    • 생명과학회지
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    • 제31권10호
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    • pp.954-959
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    • 2021
  • 세포 사멸은 항상성을 유지하기 위해 세포군을 조절하는 중요한 메커니즘이며 시스테인 단백질분해효소 중 하나인 카스파제는 세포 사멸 경로의 중요한 중재자이다. Caspase-8은 세포외 자극에 의해 시작되는 외인성 세포자멸 경로의 개시자 카스파제이다. Caspase-8에는 보존된 도메인인 N-말단의 두개의 죽음 이펙터 도메인(DED)과 C-말단의 2개의 촉매 도메인을 가지며, 이는 이러한 외인성 세포자멸 경로에 중요하게 작용한다. 외인성 세포멸사 경로에서, TNF 슈퍼패밀리인 죽음 수용체는 세포 외부로부터의 죽음 수용체 특이적 리간드의 결합에 의해 활성화된다. 활성화된 죽음 수용체가 어댑터 단백질인 Fas-associated death domain 단백질(FADD)을 모집한 후, 죽음 수용체와 FADD의 죽음 도메인(DD)이 서로 결합하고 죽음 수용체와 결합한 FADD가 caspase-8의 전구체 형태인 procaspase-8을 모집한다. FADD와 procaspase-8의 죽음 이펙터 도메인은 서로 결합하고 FADD에 결합된 procaspase-8은 prodomain의 절단에 의해 활성화된다. 이 죽음 수용체-FADD-caspase-8 복합체는 세포사멸 유도 신호복합체(DISC)라고 한다. 세포 FLICE 억제 단백질(c-FLIPs)은 세포사멸을 억제하는 역할과 촉진하는 역할을 모두 수행하여 caspase-8의 활성화를 조절하고 caspase-8 활성화는 caspase-3와 같은 작동자 카스파제를 활성화를 시킨다. 마지막으로 활성화된 작동자 카스파제는 DNA 분해, 핵 응축, 세포막 수포 및 카스파제 기질의 단백질 분해에 작용하여 세포사멸을 완료한다.

스피루리나 효소가수분해물의 생리활성 탐색 (Investigation of Biological Activities of Enzymatic Hydrolysate of Spirulina)

  • 손민희;박근형;최아름;유귀재;인만진;김동호;채희정
    • 한국식품영양과학회지
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    • 제38권2호
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    • pp.136-141
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    • 2009
  • 스피루리나를 세포벽 가수분해효소와 단백질 가수분해효소로 처리하여 조제한 스피루리나 가수분해물(enzymatic hydrolysate of spirulina, EHS)의 생리활성을 조사하였다. 효소처리 가수분해물의 유산균 증식효과, 항산화능, 암세포 증식저해 활성, 항혈전 활성을 분석한 결과 EHS는 유산균 증식활성과 항산화능에 큰 영향을 미치지 않았으며, 자궁경부암세포(HeLa)에 대해 1.42 mg/L의 농도에서 15% 미만의 증식저해효과를 나타내었다. 반면 항혈전 활성을 공통 경로(common pathway), 내인성 경로(intrinsic pathway), 외인성 경로(extrinsic pathway)로 구분하여 측정한 결과, 공통경로, 내인성 경로와 유사한 항혈전 활성이 있음을 확인하였다. 공통 경로를 thrombin time assay로 측정한 결과 EHS의 농도가 100 mg/L일 때 155.6초를 나타내었다. 내인성 경로는 activated partial thromboplastin time assay로 측정하였고, EHS의 농도가 1000 mg/L일 때 95.8초를 나타내었다. 외인성 경로를 prothrombin time assay로 측정한 결과 EHS의 농도가 1000 mg/L일 때 10.6초를 나타내었다. 결과적으로 스피루리나 효소가수분해물(EHS)이 항혈전경로 중 공통경로와 내인성 경로에 활성이 있음을 알 수 있었으며, 이를 토대로 신규의 항혈전 기능성 원료로 개발될 수 있을 것으로기대된다.

Apoptotic Effects of Cordycepin Through the Extrinsic Pathway and p38 MAPK Activation in Human Glioblastoma U87MG Cells

  • Baik, Ji-Sue;Mun, Seo-Won;Kim, Kyoung-Sook;Park, Shin-Ji;Yoon, Hyun-Kyoung;Kim, Dong-Hyun;Park, Min-Kyu;Kim, Cheorl-Ho;Lee, Young-Choon
    • Journal of Microbiology and Biotechnology
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    • 제26권2호
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    • pp.309-314
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    • 2016
  • We first demonstrated that cordycepin inhibited cell growth and triggered apoptosis in U87MG cells with wild-type p53, but not in T98G cells with mutant-type p53. Western blot data revealed that the levels of procaspase-8, -3, and Bcl-2 were downregulated in cordycepin-treated U87MG cells, whereas the levels of Fas, FasL, Bak, cleaved caspase-3, -8, and cleaved PARP were upregulated, indicating that cordycepin induces apoptosis by activating the death receptor-mediated pathway in U87MG cells. Cordycepin-induced apoptosis could be suppressed by only SB203580, a p38 MAPK-specific inhibitor. These results suggest that cordycepin triggered apoptosis in U87MG cells through p38 MAPK activation and inhibition of the Akt survival pathway.

HepG2 인체 간암세포의 ROS 생성 및 ERK/Akt 신호전달 경로 조절을 통한 sanguinarine의 apoptosis 유도 (Sanguinarine Induces Apoptosis in Human Hepatocellular Carcinoma HepG2 Cells through the Generation of ROS and Modulation of Akt/ERK Signaling Pathways)

  • 황주영;최영현
    • 생명과학회지
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    • 제25권9호
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    • pp.984-992
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    • 2015
  • 혈근초(Sanguinaria canadensis)에서 처음 분리된 sanguinarine은 항산화, 항암 및 면역 증강 등의 효능이 있는 것으로 알려진 alkaloid 계열 물질 중의 하나이다. 본 연구에서는 인체간암 HepG2 세포를 대상으로 sanguinarine의 apoptosis 유도 효능 및 관련 기전 해석을 시도하였다. 본 연구의 결과에 의하면 sanguinarine은 HepG2 간암세포의 증식을 처리 농도 의존적으로 억제하였으며, 이는 apoptosis 유도와 연관성이 있었다. Sanguinarine에 의한 apoptosis 유도에는 Fas 및 Bax의 발현 증가, 미토콘드리아에서 세포질로의 cytochrome c 유리 및 MMPl (Δψm)의 소실을 동반하였다. Sanguinarine은 intrinsic 및 extrinsic apoptosis pathway의 활성에 관여하는 initiator caspase인 caspase-9와 -8의 활성과 effector caspase인 caspase-3의 활성 및 PARP 단백질의 단편화를 유발하였다. Sanguinarine은 또한 ROS의 생성을 촉진시켰으며, N-acetylcysteine 처리에 의한 ROS의 생성을 차단하였을 경우, sanguinarine에 의한 apoptosis 효능이 완벽하게 차단되었다. 아울러 sanguinarine은 Akt의 인산화를 억제한 반면, MAPKs의 인산화를 촉진시켰으며, 특히 PI3K와 ERK의 선택적 억제제는 sanguinarine에 의한 HepG2 간암세포의 증식을 더욱 억제시켰다. 따라서 sanguinarine에 의한 HepG2 간암세포의 apoptosis 유발에는 ROS 생성 의존적인 intrinsic 및 extrinsic signaling pathway가 동시에 활성화되며, PI3K/Akt 및 ERK 신호계가 관여함을 알 수 있었다.