• Title/Summary/Keyword: BAX protein

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Identification of Inhibitors Against BAK Pore Formation using an Improved in vitro Assay System

  • Song, Seong-Soo;Lee, Won-Kyu;Aluvila, Sreevidya;Oh, Kyoung Joon;Yu, Yeon Gyu
    • Bulletin of the Korean Chemical Society
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    • v.35 no.2
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    • pp.419-424
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    • 2014
  • The pro-apoptotic BCL-2 family protein BID activates BAK and/or BAX, which form oligomeric pores in the mitochondrial outer membrane. This results in the release of cytochrome c into the cytoplasm, initiating the apoptotic cascade. Here, we utilized liposomes encapsulating sulfo-rhodamine at a controlled temperature to improve upon a previously reported assay system with enhanced sensitivity and specificity for measuring membrane permeabilization by BID-dependent BAK activation. BAK activation was inhibited by BCL-$X_L$ protein but not by a mutant protein with impaired anti-apoptotic activity. With the assay system, we screened a chemical library and identified several compounds including trifluoperazine, a mitochondrial apoptosis-induced channel blocker. It inhibited BAK activation by direct binding to BAK and blocking the oligomerization of BAK.

Effects of Polygalae Radix Preparata Cum Glycyrrhizae Radix on 4-HNE-induced Apoptosis in PC-12 cell (지감초자(志甘草煮)가 4-HNE로 유도된 Apoptosis에 미치는 영향)

  • Ham, Mee-Jin;Kim, Youn-Sub
    • The Korea Journal of Herbology
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    • v.31 no.1
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    • pp.77-82
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    • 2016
  • Objectives : The study was designed to observe the effect of Polygalae Radix Preparata Cum Glycyrrhizae Radix on 4-Hydroxynonenal (4-HNE)-induced apoptosis in PC-12 cell.Methods : A cytotoxic test on Polygalae Radix Preparata Cum Glycyrrhizae Radix (PG) was conducted and another MTT assay was conducted to observe the cytoprotective effect against 4-HNE that cause oxidative stress. In addition, in order to observe the expression of Bax, Bcl-2, Caspase-3 and TNF-α protein involved with apoptosis, western blot was conducted.Results : The groups treated with 25 ㎍, 50 ㎍ and 100 ㎍ of PG water extract had no toxicity for PC-12 cell. The groups treated with 25 ㎍, 50 ㎍ and 100 ㎍ of PG water extract showed a significant increase of cell survival rate in comparison with the control group injected by only 4-HNE. The groups treated with 25 ㎍ and 50 ㎍ of PG water extract showed a significant supression on increase of Bax protein expression in the control group. The group treated with 100 ㎍ of PG water extract showed a significant promotion on decrease of Bcl-2 protein expression in the control group. The group treated with 50 ㎍ of PG water extract showed a significant supression on increase of Caspase-3 protein expression in the control group. The group treated with 25 ㎍ of PG water extract showed a significant supression on increase of TNF-α protein expression in the control group.Conclusions : These results suggest that Polygalae Radix Preparata Cum Glycyrrhizae Radix is effective in reducing apoptosis by 4-HNE-dameged cell.

Effects of Polygalae Radix on Apotosis in PC-12 Cell (원지(遠志)물추출물이 Apoptosis에 미치는 효과)

  • Lee, Sang-Chul;Kim, Youn-Sub
    • The Korea Journal of Herbology
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    • v.30 no.1
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    • pp.59-65
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    • 2015
  • Objectives : The purpose of this study was to observe the effects of Polygalae Radix(PR) on 4-HNE-induced apoptosis in PC-12 cell. Methods : A MTT assay was conducted to observe the cytotoxicity of Polygalae Radix on the cell viability and the cytoprotective effect of Polygalae Radix against 4-HNE that causes oxidative stress-induced cytotoxicity, and then a western blot was conducted to observe the expression of $TNF-{\alpha}$, caspase-3, Bax and Bcl-2 protein that are important factors involved with apoptosis signaling pathway. Results : The Polygalae Radix water extract $25{\mu}g$, $50{\mu}g$, $100{\mu}g$ and $200{\mu}g/mL$ had no cytotoxicity on the PC-12 cell. The Polygalae Radix water extract $25{\mu}g$, $50{\mu}g$ and $100{\mu}g/mL$ had the cytoprotective effect against 4-HNE that causes cytotoxicity on the PC-12 cell. The Polygalae Radix water extract $50{\mu}g/mL$ significantly suppressed the increase in $TNF-{\alpha}$ protein expression in PC-12 cell. The Polygalae Radix water extract $25{\mu}g$ and $50{\mu}g/mL$ significantly suppressed the increase in caspase-3 protein expression in PC-12 cell. The Polygalae Radix water extract $25{\mu}g$, $50{\mu}g$ and $100{\mu}g/mL$ suppressed the increase in Bax protein expression in PC-12 cell but had no significance. The Polygalae Radix water extract $25{\mu}g$ and $100{\mu}g/mL$ significantly prevented the decrease in Bcl-2 protein expression in PC-12 cell, Conclusions : These results suggest that the Polygalae Radix water extract is effective in inhibiting apoptosis.

Paricalcitol attenuates indoxyl sulfate-induced apoptosis through the inhibition of MAPK, Akt, and NF-κB activation in HK-2 cells

  • Park, Jung Sun;Choi, Hoon In;Bae, Eun Hui;Ma, Seong Kwon;Kim, Soo Wan
    • The Korean journal of internal medicine
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    • v.34 no.1
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    • pp.146-155
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    • 2019
  • Background/Aims: Indoxyl sulfate (IS) is a uremic toxin and an important causative factor in the progression of chronic kidney disease. Recently, paricalcitol (19-nor-1,25-dihydroxyvitamin D2) was shown to exhibit protective effects in kidney injury. Here, we investigated the effects of paricalcitol treatment on IS-induced renal tubular injury. Methods: The fluorescent dye 2',7'-dichlorofluorescein diacetate was used to measure intracellular reactive oxygen species (ROS) following IS administration in human renal proximal tubular epithelial (HK-2) cells. The effects of IS on cell viability were determined using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays and levels of apoptosis-related proteins (Bcl-2-associated protein X [Bax] and B-cell lymphoma 2 [Bcl-2]), nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) p65, and phosphorylation of mitogen-activated protein kinase (MAPK) and protein kinase B (Akt) were determined by semiquantitative immunoblotting. The promoter activity of $NF-{\kappa}B$ was measured by luciferase assays and apoptosis was determined by f low cytometry of cells stained with f luorescein isothiocyanate-conjugated Annexin V protein. Results: IS treatment increased ROS production, decreased cell viability and induced apoptosis in HK-2 cells. IS treatment increased the expression of apoptosis-related protein Bax, decreased Bcl-2 expression, and activated phosphorylation of MAPK, $NF-{\kappa}B$ p65, and Akt. In contrast, paricalcitol treatment decreased Bax expression, increased Bcl-2 expression, and inhibited phosphorylation of MAPK, $NF-{\kappa}B$ p65, and Akt in HK-2 cells. $NF-{\kappa}B$ promoter activity was increased following IS, administration and was counteracted by pretreatment with paricalcitol. Additionally, flow cytometry analysis revealed that IS-induced apoptosis was attenuated by paricalcitol treatment, which resulted in decreased numbers of fluorescein isothiocyanate-conjugated Annexin V positive cells. Conclusions: Treatment with paricalcitol inhibited IS-induced apoptosis by regulating MAPK, $NF-{\kappa}B$, and Akt signaling pathway in HK-2 cells.

Induction of the Intrinsic Apoptotic Pathway by 3-Deazaadenosine Is Mediated by BAX Activation in HL-60 Cells

  • Lee, Sun-Young;Ko, Kyoung-Won;Kang, Won-Kyung;Choe, Yun-Jeong;Kim, Yoon-Hyoung;Kim, In-Kyung;Kim, Jin;Kim, Ho-Shik
    • The Korean Journal of Physiology and Pharmacology
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    • v.14 no.6
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    • pp.407-412
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    • 2010
  • 3-Deazaadenosine (DZA), a potent inhibitor of S-adenosylhomocysteine hydrolase, was previously proposed to induce intrinsic apoptosis in human leukemic cells. In the present study, we analyzed the mechanism underlying the DZA-induced intrinsic apoptotic pathway. DZA activated typical caspase-dependent apoptosis in HL-60 cells, as demonstrated by an accumulation of hypo-diploidic cells, the processing of multiple procaspases and an inhibitory effect of z-VAD-Fmk on this cell death. During DZA-induced apoptosis, cytochrome c (cyt c) was released into the cytosol. This was neither prevented by z-VAD-Fmk and nor was it associated with the dissipation of mitochondrial membrane potential (${\Delta}{\Psi}_m$). Prior to the release of cyt c, BAX was translocated from the cytosol to mitochondria and underwent oligomerization. Finally, the overexpression of BCL-XL protected HL-60 cells from apoptosis by blocking both the cyt c release and BAX oligomerization. Collectively, these findings suggest that DZA may activate intrinsic apoptosis by stimulating BAX activation and thereby the release of cyt c.

Herba Portulacae induced Apoptosis in Human CervicalCarcinoma HeLa Cells (마치현(馬齒莧)이 자궁경부암세포(子宮頸部癌細胞)(HeLa Cell)에 미치는 영향(影響))

  • Eum, Joo-Oh;Kang, Bok-Hwan;Kim, Yang-Ho;Yoo, Sim-Keun
    • The Journal of Korean Obstetrics and Gynecology
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    • v.18 no.1
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    • pp.29-44
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    • 2005
  • To address the ability of Herba Portulacae(HP) to induce cell death, we investigated the effect of HP on cell viability. Twenty-four hours later, loss of viability occurred following HP exposure in a dose-dependent manner. The treatment of HP, a commonly used herb formulation in Korea, Japan and China, caused a decrease in cell viability. HP also resulted in apoptotic morphology a brightly blue-fluorescent condensed nuclei by Hoechst 33258-staining, and reduction of cell volume. Our results show that 2mg/ml HP induces mitochondria membrane potential collapse. Immunoblotting data also shows that the expression of Bcl-2, antiaoptotic protein, decrease by the addition of HP. This GFP-Bax overexpression system shows that an important pro-apoptotic Bcl-2-family protein, Bax is translocated to mitochondria by the addition of 2mg/ml HP. Inerestingly, MAPK inhibitor study shows that p38 MAPK inhibitor, SB203580 inhibits HP-induced cell death and caspase-3 activation in HP-treated HeLa cells. Furthermore, HP transiently but significantly induces p38 activation. But P38 MAPK inhibitor does not have any effect on the translocation of Bax. Considering these results, HP induces apoptosis via p38 MAPK activation. But the pathway does not involve the translocation of Bax.

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The Study on Apoptosis and Expression of Fas, Fas-ligand, Bax, and Bcl-2 in Human Fragmented Embryos (분절화된 인간 배아에서 세포자연사와 Fas, Fas-ligand, Bax, Bcl-2 발현에 관한 연구)

  • Kim, Jong-Sik;Kim, Myoung-Shin;Yang, Hyun-Won;Yu, Chai-Hyeock;Yoon, Yong-Dal;Bae, In-Ha;Jung, Byeong-Jun;Song, Hyun-Jin
    • Clinical and Experimental Reproductive Medicine
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    • v.29 no.3
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    • pp.167-178
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    • 2002
  • Objective : The present study was performed to investigate whether apoptosis occur in human embryos by annexin staining and detect the expression of Fas, Fas-ligand (FasL), Bax, and Bcl-2 in human fragmented embryos derived from IVF-ET by immunofluorescence and Western blot analysis. Materials and Methods: Using annexin staining, immunofluorescence and Western blot analysis on normal and fragmented embryos, we were able to detect apoptotsis and apoptotic gene products in fragmented embryos. Result: Phosphatidylserine (PS) translocation, the marker for apoptosis, were detected frequently in fragmented embryos. Bcl-2 and Bax protein were detected in both fragmented and non-fragmented embryos. When fragmented embryos compared to normal embryos, immunofluorescent intensity of Bcl-2 tended to be lower in fragmented embryos. Bax gene expression increased in the fragmented embryos compared to the normal embryos. This result supports a model in which the molar ratio of Bcl-2 to Bax determines whether apoptosis induced or inhibited in human embryo. Fas was highly expressed in human preimplantation embryos but not FasL. It suggests that embryo may undergo apoptosis by binding with FasL produced by follicular or immune cells. Conclusion: The over expression of Bax and Fas will trigger apoptosis to lead embryo fragmentation and change embryo to be nonviable.

Screening of BCL-2 associated X protein gene polymorphism associated with scrotal hernia in domesticated swine using polymerase chain reaction-restriction fragment length polymorphism

  • Manalaysay, Jessica G.;Antonio, Nathaniel D.;Apilado, Ralph Lorenz R.;Bambico, Joseph F.;Mingala, Claro N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.2
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    • pp.262-266
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    • 2017
  • Objective: This study was conducted to screen scrotal hernia in domesticated swine from selected breeders in the Philippines. This defect is associated with a cytosine to thymine mutation in the BCL-2 associated X protein (BAX) gene of swine. Methods: Genetic screening was done by DNA extraction followed by amplification and digestion using polymerase chain reaction-restriction fragment length polymorphism, amplifying the 416 bp region of the BAX gene that was subjected to digestion using the Ear I enzyme. Sequencing was also conducted to validate the results. Results: Results revealed that out of 538 samples tested, 411 (76.4%) of the samples were found to be normal whereas the remaining were carriers of the mutation in which 80 (14.9%) were heterozygous mutants and 47 (8.7%) were homozygous mutants. Pietrain breed was found to have the highest incidence. Conclusion: Having a scrotal hernia eliminates the chances of using the boar as a breeder stock because the following generations arising from it would most likely exhibit herniation. It is therefore advised to establish a genetic screening method for Scrotal Hernia in the Philippines to eliminate the negative gene from the herd.

Effects of Citrus Reticulata on the Cell Detachment and Apoptosis in Human Gastric Cancer SNU-668 Cells

  • Kim, Jeung-Beum;Kim, Min-Su;Kim, Ee-Hwa;Kim, Sung-Hoon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.1
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    • pp.212-217
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    • 2005
  • The purpose of this study was to examine the effects of Citrus Reticulata(CR) on the Cell Detachment and Apoptosis in Human Gastric Cancer SNU-668 Cells. The effect of CR on apoptosis was investigated through MTT assay, DAPI staining, and TUNEL assay. We also performed RT-PCR for apoptotic genes including BCL-2, BAX, and caspase-3, the caspase-3 activity assay, and western blotting for pro-CASP-3. Then, to detect that adhesion of cell to ECM was reduced by CR, we investigated mRNA expression of CDH1 and PTK2 using RT-PCR, and their protein expressions using western blotting, and immunocytochemistry in SNU-668 cells. In this study, the results showed that treatment of CR induced time and dose-dependent cell death in SNU-668 cells. Downregulated mRNA expression of BCL-2, and upregulated mRNA expressions of BAX and CASP-3 indicated that the cell death was due to apoptosis. Protein expression of inactivated CASP-3, and caspase-3 activity assay also showed that apoptosis was induced in CR-treated cells.

Protective effect of Korean Red Ginseng against chemotherapeutic drug-induced premature catagen development assessed with human hair follicle organ culture model

  • Keum, Dong In;Pi, Long-Quan;Hwang, Sungjoo Tommy;Lee, Won-Soo
    • Journal of Ginseng Research
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    • v.40 no.2
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    • pp.169-175
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    • 2016
  • Background: Chemotherapy-induced alopecia (CIA) is one of the most distressing side effects for patients undergoing chemotherapy. This study evaluated the protective effect of Korean Red Ginseng (KRG) on CIA in a well-established in vitro human hair follicle organ culture model as it occurs in vivo. Methods: We examined whether KRG can prevent premature hair follicle dystrophy in a human hair follicle organ culture model during treatment with a key cyclophosphamide metabolite, 4-hydroperoxycyclophosphamide (4-HC). Results: 4-HC inhibited human hair growth, induced premature catagen development, and inhibited proliferation and stimulated apoptosis of hair matrix keratinocytes. In addition, 4-HC increased p53 and Bax protein expression and decreased Bcl2 protein expression. Pretreatment with KRG protected against 4-HC-induced hair growth inhibition and premature catagen development. KRG also suppressed 4-HC-induced inhibition of matrix keratinocyte proliferation and stimulation of matrix keratinocyte apoptosis. Moreover, KRG restored 4-HC-induced p53 and Bax/Bcl2 expression. Conclusion: Overall, our results indicate that KRG may protect against 4-HC-induced premature catagen development through modulation of p53 and Bax/Bcl2 expression.