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Blombery P, Lew TE, Dengler MA, Thompson ER, Lin VS, Chen X, Nguyen T, Panigrahi A, Handunnetti SM, Carney DA, Westerman DA, Tam CS, Adams JM, Wei AH, Huang DC, Seymour JF, Roberts AW, Anderson MA. Clonal hematopoiesis, myeloid disorders and BAX-mutated myelopoiesis in patients receiving venetoclax for CLL. Blood 2022; 139:1198-1207. [PMID: 34469514 PMCID: PMC11017791 DOI: 10.1182/blood.2021012775] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 08/13/2021] [Indexed: 11/20/2022] Open
Abstract
The BCL2 inhibitor venetoclax has established therapeutic roles in chronic lymphocytic leukemia (CLL) and acute myeloid leukemia (AML). As BCL2 is an important determinant of survival of both myeloid progenitor and B cells, we investigated whether clinical and molecular abnormalities arise in the myeloid compartment during long-term continuous venetoclax treatment of CLL in 89 patients (87 with relapsed/refractory CLL). Over a median follow-up of 75 (range 21-98) months, persistent cytopenias (≥1 of neutropenia, thrombocytopenia, anemia) lasting ≥4 months and unrelated to CLL occurred in 25 patients (28%). Of these patients, 20 (80%) displayed clonal hematopoiesis, including 10 with therapy-related myeloid neoplasms (t-MNs). t-MNs occurred exclusively in patients previously exposed to fludarabine-alkylator combination therapy with a cumulative 5-year incidence of 10.4% after venetoclax initiation, consistent with rates reported for patients exposed to fludarabine-alkylator combination therapy without venetoclax. To determine whether the altered myelopoiesis reflected the acquisition of mutations, we analyzed samples from patients with no or minimal bone marrow CLL burden (n = 41). Mutations in the apoptosis effector BAX were identified in 32% (13/41). In cellular assays, C-terminal BAX mutants abrogated outer mitochondrial membrane localization of BAX and engendered resistance to venetoclax killing. BAX-mutated clonal hematopoiesis occurred independently of prior fludarabine-alkylator combination therapy exposure and was not associated with t-MNs. Single-cell sequencing revealed clonal co-occurrence of mutations in BAX with DNMT3A or ASXL1. We also observed simultaneous BCL2 mutations within CLL cells and BAX mutations in the myeloid compartment of the same patients, indicating lineage-specific adaptation to venetoclax therapy.
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MESH Headings
- Aged
- Aged, 80 and over
- Antineoplastic Combined Chemotherapy Protocols/administration & dosage
- Antineoplastic Combined Chemotherapy Protocols/adverse effects
- Bridged Bicyclo Compounds, Heterocyclic/administration & dosage
- Bridged Bicyclo Compounds, Heterocyclic/adverse effects
- Female
- Hematologic Neoplasms/genetics
- Hematologic Neoplasms/metabolism
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/genetics
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Male
- Middle Aged
- Mutation
- Myelopoiesis/drug effects
- Myeloproliferative Disorders/genetics
- Myeloproliferative Disorders/metabolism
- Neoplasms, Second Primary/genetics
- Neoplasms, Second Primary/metabolism
- Sulfonamides/administration & dosage
- Sulfonamides/adverse effects
- Vidarabine/administration & dosage
- Vidarabine/adverse effects
- Vidarabine/analogs & derivatives
- bcl-2-Associated X Protein/antagonists & inhibitors
- bcl-2-Associated X Protein/genetics
- bcl-2-Associated X Protein/metabolism
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Affiliation(s)
- Piers Blombery
- Department of Clinical Haematology, Peter MacCallum Cancer Centre and Royal Melbourne Hospital, Melbourne, VIC, Australia
- Department of Pathology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Thomas E. Lew
- Department of Clinical Haematology, Peter MacCallum Cancer Centre and Royal Melbourne Hospital, Melbourne, VIC, Australia
- Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
| | - Michael A. Dengler
- University of Melbourne, Melbourne, VIC, Australia
- Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- Division on Oncology, Medical University of Graz, Graz, Austria
| | - Ella R. Thompson
- University of Melbourne, Melbourne, VIC, Australia
- Department of Pathology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Victor S. Lin
- Department of Clinical Haematology, Peter MacCallum Cancer Centre and Royal Melbourne Hospital, Melbourne, VIC, Australia
- University of Melbourne, Melbourne, VIC, Australia
- Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
| | - Xiangting Chen
- Department of Pathology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Tamia Nguyen
- Department of Pathology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Ashish Panigrahi
- Department of Clinical Haematology, Peter MacCallum Cancer Centre and Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Sasanka M. Handunnetti
- Department of Clinical Haematology, Peter MacCallum Cancer Centre and Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Dennis A. Carney
- Department of Clinical Haematology, Peter MacCallum Cancer Centre and Royal Melbourne Hospital, Melbourne, VIC, Australia
- University of Melbourne, Melbourne, VIC, Australia
| | - David A. Westerman
- Department of Clinical Haematology, Peter MacCallum Cancer Centre and Royal Melbourne Hospital, Melbourne, VIC, Australia
- Department of Pathology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Constantine S. Tam
- Department of Clinical Haematology, Peter MacCallum Cancer Centre and Royal Melbourne Hospital, Melbourne, VIC, Australia
- University of Melbourne, Melbourne, VIC, Australia
| | - Jerry M. Adams
- University of Melbourne, Melbourne, VIC, Australia
- Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
| | - Andrew H. Wei
- The Alfred Hospital and Monash University, Melbourne, VIC, Australia
| | - David C.S. Huang
- University of Melbourne, Melbourne, VIC, Australia
- Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
| | - John F. Seymour
- Department of Clinical Haematology, Peter MacCallum Cancer Centre and Royal Melbourne Hospital, Melbourne, VIC, Australia
- University of Melbourne, Melbourne, VIC, Australia
| | - Andrew W. Roberts
- Department of Clinical Haematology, Peter MacCallum Cancer Centre and Royal Melbourne Hospital, Melbourne, VIC, Australia
- University of Melbourne, Melbourne, VIC, Australia
- Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
| | - Mary Ann Anderson
- Department of Clinical Haematology, Peter MacCallum Cancer Centre and Royal Melbourne Hospital, Melbourne, VIC, Australia
- Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
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Wong HY, Hui Q, Hao Z, Warnock GL, Woo M, Luciani DS, Marzban L. The role of mitochondrial apoptotic pathway in islet amyloid-induced β-cell death. Mol Cell Endocrinol 2021; 537:111424. [PMID: 34400259 DOI: 10.1016/j.mce.2021.111424] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 07/24/2021] [Accepted: 08/10/2021] [Indexed: 12/16/2022]
Abstract
Islet amyloid, formed by aggregation of human islet amyloid polypeptide (hIAPP), contributes to β-cell death in type 2 diabetes. We previously showed that extracellular hIAPP aggregates promote Fas-mediated β-cell apoptosis. Here, we tested if hIAPP aggregates can trigger the mitochondrial apoptotic pathway (MAP). hIAPP aggregation in Ad-hIAPP transduced INS-1 and human islet β-cells promoted cytochrome c release, caspase-9 activation and apoptosis, which were reduced by Bax inhibitor. Amyloid formation in hIAPP-expressing mouse islets during culture increased caspase-9 activation in β-cells. Ad-hIAPP transduced islets from CytcKA/KA and BaxBak βDKO mice (models of blocked MAP), had lower caspase-9-positive and apoptotic β-cells than transduced wild-type islets, despite comparable amyloid formation. Blocking Fas (markedly) and Bax or caspase-9 (modestly) reduced β-cell death induced by extracellular hIAPP aggregates. These findings suggest a role for MAP in amyloid-induced β-cell death and a potential strategy to reduce intracellular amyloid β-cell toxicity by blocking cytochrome c apoptotic function.
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Affiliation(s)
- Helen Y Wong
- Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Queenie Hui
- Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Zhenyue Hao
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada
| | - Garth L Warnock
- Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Minna Woo
- Toronto General Hospital Research Institute and Division of Endocrinology, Department of Medicine, University of Toronto, Toronto, ON, Canada
| | - Dan S Luciani
- Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada; BC Children's Hospital Research Institute, Vancouver, BC, Canada
| | - Lucy Marzban
- Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada; College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada.
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Mao L, Zeng Q, Su W, Song M, Li J, Xie M. Elevation of miR-146a Inhibits BTG2/BAX Expression to Ameliorate Postoperative Cognitive Dysfunction Following Probiotics (VSL#3) Treatment. Mol Neurobiol 2021; 58:3457-3470. [PMID: 33725320 DOI: 10.1007/s12035-021-02330-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 02/11/2021] [Indexed: 12/12/2022]
Abstract
It has been reported that the gut microbiome modulates postoperative cognitive dysfunction (POCD), and that administration of probiotics (VSL#3) may effectively relieve POCD. In this study, we aimed to identify the underlying mechanism of VSL#3 in POCD. A mouse model of POCD was constructed in adult male C57BL/6 mice, which were then treated with VSL#3. VSL#3 exerted a protective role against POCD and resultant neuronal apoptosis. The expression of miR-146a was found to be downregulated in hippocampal tissues of POCD mice, while VSL#3 could restore its expression. Loss- and gain-function approaches were conducted to determine the roles of microRNA (miR)-146a, B-cell translocation gene 2 (BTG2), and Bcl-2-associated X protein (Bax) in post-operative effects on cognitive function and neuronal apoptosis. The levels of reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD) were measured to determine oxidative stress in brain tissue. The dual-luciferase reporter gene assay identified that miR-146a could target BTG2 and negatively regulate its expression. BTG2 knockdown suppressed neuronal apoptosis and contributed to shortened time of latency, prolonged time of mice spent in the target quadrant, and reduced oxidative stress through downregulating Bax expression. Finally, VSL#3 treatment upregulated the expression of miR-146a to block BTG2/Bax axis and consequently inhibited neuronal apoptosis and reduced oxidative stress in POCD mice. Taken together, the study suggested that miR-146a-mediated suppression of BTG2/Bax contributed to the protective role of probiotics treatment against POCD.
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Affiliation(s)
- Lei Mao
- Department of Anesthesiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, No. 32, West Second Section, First Ring Road, Qingyang District, Chengdu, 610072, Sichuan Province, People's Republic of China
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, No. 32, West Second Section, First Ring Road, Qingyang District, Chengdu, 610072, Sichuan Province, People's Republic of China
| | - Qingcui Zeng
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, No. 32, West Second Section, First Ring Road, Qingyang District, Chengdu, 610072, Sichuan Province, People's Republic of China
- Geriatric Intensive Care Unit, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, People's Republic of China
| | - Wenjie Su
- Department of Anesthesiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, No. 32, West Second Section, First Ring Road, Qingyang District, Chengdu, 610072, Sichuan Province, People's Republic of China
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, No. 32, West Second Section, First Ring Road, Qingyang District, Chengdu, 610072, Sichuan Province, People's Republic of China
| | - Menglong Song
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, No. 32, West Second Section, First Ring Road, Qingyang District, Chengdu, 610072, Sichuan Province, People's Republic of China
- Emergency Intensive Care Unit, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, People's Republic of China
| | - Jiacen Li
- Department of Anesthesiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, No. 32, West Second Section, First Ring Road, Qingyang District, Chengdu, 610072, Sichuan Province, People's Republic of China.
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, No. 32, West Second Section, First Ring Road, Qingyang District, Chengdu, 610072, Sichuan Province, People's Republic of China.
| | - Min Xie
- Department of Anesthesiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, No. 32, West Second Section, First Ring Road, Qingyang District, Chengdu, 610072, Sichuan Province, People's Republic of China.
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, No. 32, West Second Section, First Ring Road, Qingyang District, Chengdu, 610072, Sichuan Province, People's Republic of China.
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Park IS, Seo HR, Kim K, Lee H, Shum D, Choi I, Kim J. Identification of inhibitors of Bcl-2 family protein-protein interaction by combining the BRET screening platform with virtual screening. Biochem Biophys Res Commun 2020; 527:709-715. [PMID: 32423828 DOI: 10.1016/j.bbrc.2020.05.045] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 05/07/2020] [Indexed: 11/19/2022]
Abstract
Bcl-2 family proteins play key roles in tumor initiation, progression, and resistance to therapy. Therefore, the protein-protein interactions (PPIs) between the pro-survival proteins, B-cell lymphoma (Bcl)-2 and Bcl-xL, and the pro-apoptotic proteins, Bax and Bak, could be attractive therapeutic targets for anti-cancer drug discovery. Here, we found new small molecules, BIP-A1001 and BIP-A2001 that modulated Bak/Bax and Bcl-xL interactions by combining the Nanoluc/YFP-based bioluminescence resonance energy transfer (BRET) assay with structure based virtual screening. In addition, we chose compounds with similar structures to BIP-A1001 and BIP-A2001 and tested their inhibitory effects using the BRET assay as a dose-response function. The results indicated that identifying compounds that inhibit interactions between Bak/Bax and Bcl-xL could be a promising approach to enhance cancer therapy.
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Affiliation(s)
- I-Seul Park
- Screening Discovery Platform, Institut Pasteur Korea, 16, Daewangpangyo-ro 712 beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, South Korea
| | - Haeng Ran Seo
- Cancer Biology Laboratory, Institut Pasteur Korea, 16, Daewangpangyo-ro 712 beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, South Korea
| | - Kideok Kim
- Screening Discovery Platform, Institut Pasteur Korea, 16, Daewangpangyo-ro 712 beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, South Korea
| | - Honggun Lee
- Screening Discovery Platform, Institut Pasteur Korea, 16, Daewangpangyo-ro 712 beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, South Korea
| | - David Shum
- Screening Discovery Platform, Institut Pasteur Korea, 16, Daewangpangyo-ro 712 beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, South Korea
| | - Inhee Choi
- Medicinal Chemistry, Institut Pasteur Korea, 16, Daewangpangyo-ro 712 beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, South Korea.
| | - Jiho Kim
- Screening Discovery Platform, Institut Pasteur Korea, 16, Daewangpangyo-ro 712 beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, South Korea.
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Liu Y, Chen H, Zhang L, Zhang T, Ren X. The Association Between Thyroid Injury and Apoptosis, and Alterations of Bax, Bcl-2, and Caspase-3 mRNA/Protein Expression Induced by Nickel Sulfate in Wistar Rats. Biol Trace Elem Res 2020; 195:159-168. [PMID: 31392545 DOI: 10.1007/s12011-019-01825-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 07/09/2019] [Indexed: 12/15/2022]
Abstract
To study the toxicity induced by Nickel sulfate (NiSO4) on thyroid tissue, and investigate the role of apoptosis as the possible mechanism, thirty-two male Wistar rats were randomly divided into control group (normal saline, ip), low dose group (2.5 mg/kg day NiSO4, ip), middle dose group (5 mg/kg day NiSO4, ip), high dose group (10 mg/kg day NiSO4, ip). After 40 consecutive days of treatment, there were obvious pathological changes in the thyroids of high dose group. Free T4 (FT4) and thyroid-stimulating hormone (TSH) were significantly lower in the NiSO4-treated groups than those in the control group (F = 4.992, p = 0.016; F = 4.524, p = 0.012). The mRNA expression of Caspase-3 was significantly higher (F = 10.259, p = 0.014) in all NiSO4-treated groups, and the mRNA expression of Bcl-2 was significantly lower (F = 9.225, p = 0.018) only in the high dose group. Both control group and the NiSO4-treated groups showed no changes in the mRNA expression of Bax gene. The ratio of Bcl-2/Bax decreased with the increase in exposure dose of NiSO4 (F = 13.382, p = 0.015). The mRNA expression of Fas went up in high dose group (F = 66.632, p < 0.001). The Caspase-3, Fas, and the Bax protein expressions measured by immunohistochemistry were consistent with the mRNA expression. The expression of Bcl-2 protein was significantly lower in the test groups than in the control group (F = 3.873, p = 0.025). NiSO4 as an Endocrine Disrupting Chemical may induce the thyroid injury through apoptosis and lead to hypothyroidism. Also, apoptosis in thyroid tissues was closely related to the alternations of Caspase-3, Bcl-2, and Fas mRNA and protein expression.
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Affiliation(s)
- Yahong Liu
- Department of Endocrine, The Second Hospital of Lanzhou University, Lanzhou, 730030, Gansu, People's Republic of China
- Department of Pediatrics, The Second Hospital of Lanzhou University, Lanzhou, 730030, Gansu, People's Republic of China
| | - Hui Chen
- Department of Endocrine, The Second Hospital of Lanzhou University, Lanzhou, 730030, Gansu, People's Republic of China.
| | - Li Zhang
- Department of Endocrine, The Second Hospital of Lanzhou University, Lanzhou, 730030, Gansu, People's Republic of China
| | - Tao Zhang
- Department of Endocrine, The Second Hospital of Lanzhou University, Lanzhou, 730030, Gansu, People's Republic of China
| | - Xuan Ren
- Department of Endocrine, The Second Hospital of Lanzhou University, Lanzhou, 730030, Gansu, People's Republic of China
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Gajendran B, Durai P, Madhu Varier K, Chinnasamy A. A novel phytosterol isolated from Datura inoxia, RinoxiaB is a potential cure colon cancer agent by targeting BAX/Bcl2 pathway. Bioorg Med Chem 2019; 28:115242. [PMID: 31866271 DOI: 10.1016/j.bmc.2019.115242] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 11/25/2019] [Accepted: 11/25/2019] [Indexed: 12/12/2022]
Abstract
Plant sterols have been widely used as chemotherapeutic agents for colorectal cancer for years together. In this study, a novel phytosterol was isolated and characterized from the leaf extract of a medicinal plant, Datura inoxia and was coined as RinoxiaB (RB). This phytosterol was observed to have antiproliferative activity against human colon adenocarcinoma cells, HCT 15. The cell viability assay revealed the IC50 value of the RB as 4 µM. Moreover, RB treated cells showed prominent morphological changes dose dependently and progressively increased the number of dead cells. Additionally, results of the comet, flow cytometry, and cell cycle analysis revealed that the majority of cells were arrested in their S and G2/M phase by blocking the mitotic spindle formation. The western blot analysis (Bcl-2, BAX, Cytochrome C, Caspases 9 & 3) clearly indicated that RB has the ability to induce apoptosis by significantly upregulating (P < 0.05) Bcl-2 and causing mitochondrial damage leading to Cytochrome C release and activation of caspases, which subsequently results in downregulation of BAX expression in the cytosol. Furthermore, the expression of tumor suppressors (p53 and p21) and cell cycle regulatory proteins (Cyclins D1 & B1) suggested that RB inhibit cell proliferation. Thus, the present finding concludes that RB can offer possible apoptotic effects by targeting BAX/Bcl2 pathway in HCT 15 cells, thus alleviating colon cancer.
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Affiliation(s)
- Babu Gajendran
- Department of Zoology, University of Madras, Guindy Campus, Chennai 600025, Tamil Nadu, India; State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Medical University, Guiyang 550014, Guizhou Province, People's Republic of China; Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academy of Sciences, Guiyang 550014, Guizhou Province, People's Republic of China
| | - Prabhu Durai
- Department of Zoology, University of Madras, Guindy Campus, Chennai 600025, Tamil Nadu, India
| | - Krishnapriya Madhu Varier
- Department of Zoology, University of Madras, Guindy Campus, Chennai 600025, Tamil Nadu, India; Department of Medical Biochemistry, Dr. ALM PGIBMS, University of Madras, Taramani Campus, Chennai 600113, Tamil Nadu, India
| | - Arulvasu Chinnasamy
- Department of Zoology, University of Madras, Guindy Campus, Chennai 600025, Tamil Nadu, India.
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Zhang BF, Hu Y, Liu X, Cheng Z, Lei Y, Liu Y, Zhao X, Mu M, Yu L, Cheng ML. The role of AKT and FOXO3 in preventing ovarian toxicity induced by cyclophosphamide. PLoS One 2018; 13:e0201136. [PMID: 30071053 PMCID: PMC6071999 DOI: 10.1371/journal.pone.0201136] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 07/08/2018] [Indexed: 12/11/2022] Open
Abstract
Cyclophosphamide (CTX) has immunosuppressive effects and has been wildly used as one anti-cancer drug in clinical. Significant toxicity has been noticed particularly in the reproductive system. CTX promotes the maturation of ovarian follicles, decreases follicular reserve, and ultimately lead to ovarian failure or even premature ovarian failure (POF). The placental extract (HPE) has been shown to have some beneficial impact on reproductive system; however, little is known regarding to the effect of HPE on protecting CTX-induced ovarian injury and the mechanism involved. Whether human placental extracts (HPE) has a protective effect on CTX-induced toxicity on ovarian was studied by using a CTX-induced ovarian injury animal model. The effects of HEP on histopathology, the number of atretic follicles, the weight of the ovary, serum hormone levels, and apoptosis in granulosa cells were studied in mice with CTX or control vehicle. Our results have demonstrated that HPE inhibited p-Rictor, reduced the expression of Bad, Bax and PPAR, and activated Akt and Foxo3a (increased their phosphorylation). Mice treated with HPE showed higher ovarian weight, lower number of atretic follicles, higher serum levels of the hormones E2 and progesterone, and lower apoptosis and serum levels of LH and FSH in granulosa cells, than that in the control animal group. Our data show that ovarian injury can be attenuated by HPE. HPE likely protects follicular granulosa cells from undergoing significant apoptosis and reduce atresia follicle formation, therefore, alleviates CTX-induced ovarian injury.
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Affiliation(s)
- Bao-fang Zhang
- The First Affiliated Hospital, Soochow University, Suzhou, Jiangsu, China
- The Affiliated Hospital, Guizhou Medical University, Guiyang, Guizhou, China
| | - YaXin Hu
- The Affiliated Hospital, Guizhou Medical University, Guiyang, Guizhou, China
| | - Xinyan Liu
- Shandong Institute of Biological Products,Taishan district, Shandong, China
| | - Zhuo Cheng
- Peking University Health Science Center School of Foundational Education, Beijing,China
| | - Yu Lei
- The Affiliated Hospital, Guizhou Medical University, Guiyang, Guizhou, China
| | - YongMei Liu
- The Affiliated Hospital, Guizhou Medical University, Guiyang, Guizhou, China
| | - Xueke Zhao
- The Affiliated Hospital, Guizhou Medical University, Guiyang, Guizhou, China
| | - Mao Mu
- The Affiliated Hospital, Guizhou Medical University, Guiyang, Guizhou, China
| | - Lei Yu
- The Affiliated Hospital, Guizhou Medical University, Guiyang, Guizhou, China
| | - Ming-liang Cheng
- The Affiliated Hospital, Guizhou Medical University, Guiyang, Guizhou, China
- * E-mail: (LY); (MLC)
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Fan LF, He PY, Peng YC, Du QH, Ma YJ, Jin JX, Xu HZ, Li JR, Wang ZJ, Cao SL, Li T, Yan F, Gu C, Wang L, Chen G. Mdivi-1 ameliorates early brain injury after subarachnoid hemorrhage via the suppression of inflammation-related blood-brain barrier disruption and endoplasmic reticulum stress-based apoptosis. Free Radic Biol Med 2017; 112:336-349. [PMID: 28790012 DOI: 10.1016/j.freeradbiomed.2017.08.003] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 08/02/2017] [Accepted: 08/04/2017] [Indexed: 01/12/2023]
Abstract
Aberrant modulation of mitochondrial dynamic network, which shifts the balance of fusion and fission towards fission, is involved in brain damage of various neurodegenerative diseases including Parkinson's disease, Huntington's disease and Alzheimer's disease. A recent research has shown that the inhibition of mitochondrial fission alleviates early brain injury after experimental subarachnoid hemorrhage, however, the underlying molecular mechanisms have remained to be elucidated. This study was undertaken to characterize the effects of the inhibition of dynamin-related protein-1 (Drp1, a dominator of mitochondrial fission) on blood-brain barrier (BBB) disruption and neuronal apoptosis following SAH and the potential mechanisms. The endovascular perforation model of SAH was performed in adult male Sprague Dawley rats. The results indicated Mdivi-1(a selective Drp1 inhibitor) reversed the morphologic changes of mitochondria and Drp1 translocation, reduced ROS levels, ameliorated the BBB disruption and brain edema remarkably, decreased the expression of MMP-9 and prevented degradation of tight junction proteins-occludin, claudin-5 and ZO-1. Mdivi-1 administration also inhibited the nuclear translocation of nuclear factor-kappa B (NF-κB), leading to decreased expressions of TNF-ɑ, IL-6 and IL-1ß. Moreover, Mdivi-1 treatment attenuated neuronal cell death and improved neurological outcome. To investigate the underlying mechanisms further, we determined that Mdivi-1 reduced p-PERK, p-eIF2α, CHOP, cleaved caspase-3 and Bax expression as well as increased Bcl-2 expression. Rotenone (a selective inhibitor of mitochondrial complexes I) abolished both the anti-BBB disruption and anti-apoptosis effects of Mdivi-1. In conclusion, these data implied that excessive mitochondrial fission might inhibit mitochondrial complex I to become a cause of oxidative stress in SAH, and the inhibition of Drp1 by Mdivi-1 attenuated early brain injury after SAH probably via the suppression of inflammation-related blood-brain barrier disruption and endoplasmic reticulum stress-based apoptosis.
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Affiliation(s)
- Lin-Feng Fan
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, No. 88 Jiefang Road, Hangzhou, China
| | - Ping-You He
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, No. 88 Jiefang Road, Hangzhou, China
| | - Yu-Cong Peng
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, No. 88 Jiefang Road, Hangzhou, China
| | - Qing-Hua Du
- Zhejiang University School of Medicine, China
| | - Yi-Jun Ma
- Zhejiang University School of Medicine, China
| | | | - Hang-Zhe Xu
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, No. 88 Jiefang Road, Hangzhou, China
| | - Jian-Ru Li
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, No. 88 Jiefang Road, Hangzhou, China
| | - Zhi-Jiang Wang
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, No. 88 Jiefang Road, Hangzhou, China
| | - Sheng-Long Cao
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, No. 88 Jiefang Road, Hangzhou, China
| | - Tao Li
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, No. 88 Jiefang Road, Hangzhou, China
| | - Feng Yan
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, No. 88 Jiefang Road, Hangzhou, China
| | - Chi Gu
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, No. 88 Jiefang Road, Hangzhou, China
| | - Lin Wang
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, No. 88 Jiefang Road, Hangzhou, China
| | - Gao Chen
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, No. 88 Jiefang Road, Hangzhou, China.
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Najem A, Krayem M, Salès F, Hussein N, Badran B, Robert C, Awada A, Journe F, Ghanem GE. P53 and MITF/Bcl-2 identified as key pathways in the acquired resistance of NRAS-mutant melanoma to MEK inhibition. Eur J Cancer 2017; 83:154-165. [PMID: 28738256 DOI: 10.1016/j.ejca.2017.06.033] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 06/19/2017] [Accepted: 06/27/2017] [Indexed: 01/03/2023]
Abstract
Activating mutations in Neuroblastoma RAS viral oncogene homolog (NRAS) are found in 15-30% of melanomas and are associated with a poor prognosis. Although MAP kinase kinase (MEK) inhibitors used as single agents showed a limited clinical benefit in patients with NRAS-mutant melanoma due to their rather cytostatic effect and high toxicity, their combination with other inhibitors of pathways known to cooperate with MEK inhibition may maximise their antitumour activity. Similarly, in a context where p53 is largely inactivated in melanoma, hyperexpression of Microphthalmia associated transcription factor (MITF) and its downstream anti-apoptotic targets may be the cause of the restraint cytotoxic effects of MEK inhibitors. Indeed, drug combinations targeting both mutant BRAF and MITF or one of its important targets Bcl-2 were effective in mutant BRAF melanoma but had no effect on acquired resistance. Therefore, we aimed to further investigate the downstream MITF targets that can explain this anti-apoptotic effect and to evaluate in parallel the effect of p53 reactivation on the promotion of apoptosis under MEK inhibition in a panel of Q61NRAS-mutant melanoma cells. First, we showed that MEK inhibition (pimasertib) led to a significant inhibition of cell proliferation but with a limited effect on apoptosis that could be explained by the systematic MITF upregulation. Mimicking the MITF effect via cyclic adenosine monophosphate activation conferred resistance to MEK inhibition and upregulated Bcl-2 expression. In addition, acquired resistance to MEK inhibition was associated with a strong activation of the anti-apoptotic signalling MITF/Bcl-2. More importantly, selective Bcl-2 inhibition by ABT-199 or Bcl-2 knockout using CRISPR/Cas9 system annihilated the acquired resistance and restored the sensitivity of NRAS-mutant melanoma cells to MEK inhibition. Strikingly and similarly, direct p53 reactivation (PRIMA-1Met, APR-246) also broke resistance and synergised with MEK inhibition to induce massive apoptosis in NRAS-mutant melanoma cells with wild-type or mutant p53. Hence, our data identify MITF/Bcl-2 as a key mechanism underlying resistance of NRAS-mutant melanoma cells to apoptosis by MEK inhibitors and paves the way for a promising drug combination that could prevent or reverse anti-MEK resistance in this group of patients.
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Affiliation(s)
- Ahmad Najem
- Laboratory of Oncology and Experimental Surgery, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium
| | - Mohammad Krayem
- Laboratory of Oncology and Experimental Surgery, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium
| | - François Salès
- Laboratory of Oncology and Experimental Surgery, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium; Department of Surgery, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium
| | - Nader Hussein
- Department of Biochemistry, Lebanese University, Beirut, Lebanon
| | - Bassam Badran
- Department of Biochemistry, Lebanese University, Beirut, Lebanon
| | | | - Ahmad Awada
- Medical Oncology Clinic, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium
| | - Fabrice Journe
- Laboratory of Oncology and Experimental Surgery, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium; Service d'Anatomie Humaine et d'Oncologie Expérimentale, Université de Mons, Mons, Belgium
| | - Ghanem E Ghanem
- Laboratory of Oncology and Experimental Surgery, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium.
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10
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Teymouri M, Pirro M, Johnston TP, Sahebkar A. Curcumin as a multifaceted compound against human papilloma virus infection and cervical cancers: A review of chemistry, cellular, molecular, and preclinical features. Biofactors 2017; 43:331-346. [PMID: 27896883 DOI: 10.1002/biof.1344] [Citation(s) in RCA: 138] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 10/03/2016] [Accepted: 10/05/2016] [Indexed: 12/25/2022]
Abstract
Curcumin, the bioactive polyphenolic ingredient of turmeric, has been extensively studied for its effects on human papilloma virus (HPV) infection as well as primary and malignant squamous cervical cancers. HPV infections, especially those related to HPV 16 and 18 types, have been established as the leading cause of cervical cancer; however, there are also additional contributory factors involved in the etiopathogenesis of cervical cancers. Curcumin has emerged as having promising chemopreventive and anticancer effects against both HPV-related and nonrelated cervical cancers. In this review, we first discuss the biological relevance of curcumin and both its pharmacological effects and pharmaceutical considerations from a chemical point of view. Next, the signaling pathways that are modulated by curcumin and are relevant to the elimination of HPV infection and treatment of cervical cancer are discussed. We also present counter arguments regarding the effects of curcumin on signaling pathways and molecular markers dysregulated by benzo(a)pyrene (Bap), a carcinogen found in pathological cervical lesions of women who smoke frequently, and estradiol, as two important risk factors involved in persistent HPV-infection and cervical cancer. Finally, various strategies to enhance the pharmacological activity and pharmacokinetic characteristics of curcumin are discussed with examples of studies in experimental models of cervical cancer. © 2016 BioFactors, 43(3):331-346, 2017.
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Affiliation(s)
- Manouchehr Teymouri
- Biotechnology Research Center, Nanotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, 91775-1365, Iran
| | - Matteo Pirro
- Unit of Internal Medicine, Angiology and Arteriosclerosis Diseases, Department of Medicine, University of Perugia, Italy
| | - Thomas P Johnston
- Division of Pharmaceutical Sciences School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO, USA
| | - Amirhosein Sahebkar
- Biotechnology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
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11
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Lu L, Dong J, Li D, Zhang J, Fan S. 3,3'-diindolylmethane mitigates total body irradiation-induced hematopoietic injury in mice. Free Radic Biol Med 2016; 99:463-471. [PMID: 27609226 DOI: 10.1016/j.freeradbiomed.2016.09.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 08/26/2016] [Accepted: 09/04/2016] [Indexed: 01/28/2023]
Abstract
We have reported that hematopoietic system injury induced by total body irradiation (TBI) leads to generation of intracellular reactive oxygen species (ROS) and DNA damage, which are ameliorated by antioxidant agents. In the present study, we reported that administration of DIM, a potent antioxidant agent, not only protected mice against TBI-induced lethality, also ameliorated TBI-induced hematopoietic injury. The latter effect was probably attributable to DIM's inhibition of TBI-induced increases in ROS production in hematopoietic stem cells (HSCs) and the phosphorylation of histone H2AX (γ-H2AX). In particular, DIM led to significant improvements in bone marrow (BM) HSC frequency, hematopoietic progenitor cell (HPC) clonogenic function, and multilineage engraftment after transplantation. A downregulation of NADPH oxidase 4 (NOX4) and an upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression were observed following DIM treatment. Notably, the anti-apoptotic potential of DIM was correlated with increased expression of the anti-apoptotic protein Bcl-2 and decreased expression of the pro-apoptotic protein Bax. These findings suggest that DIM attenuates TBI-induced hematopoietic injury through the inhibition of both oxidative stress in HSCs and hematopoietic cell apoptosis. Furthermore, we demonstrated that DIM protected BM hematopoietic cells against ionizing radiation and led to increased clonogenicity in vitro. Therefore, DIM has the potential to be used as an effective radioprotectant to ameliorate TBI-induced hematopoietic injury.
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Affiliation(s)
- Lu Lu
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China.
| | - Jiali Dong
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China
| | - Deguan Li
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China
| | - Junling Zhang
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China
| | - Saijun Fan
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China.
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12
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Qi L, Lv X, Zhang T, Jia P, Yan R, Li S, Zou R, Xue Y, Dai L. Cytotoxicity and genotoxicity of bacterial magnetosomes against human retinal pigment epithelium cells. Sci Rep 2016; 6:26961. [PMID: 27246808 PMCID: PMC4887902 DOI: 10.1038/srep26961] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 05/11/2016] [Indexed: 11/08/2022] Open
Abstract
A variety of nanomaterials have been developed for ocular diseases. The ability of these nanomaterials to pass through the blood-ocular barrier and their biocompatibility are essential characteristics that must be considered. Bacterial magnetosomes (BMs) are a type of biogenic magnetic nanomaterials synthesized by magnetotactic bacteria. Due to their unique biomolecular membrane shell and narrow size distribution of approximately 30 nm, BMs can pass through the blood-brain barrier. The similarity of the blood-ocular barrier to the blood-brain barrier suggests that BMs have great potential as treatments for ocular diseases. In this work, BMs were isolated from magnetotactic bacteria and evaluated in various cytotoxicity and genotoxicity studies in human retinal pigment epithelium (ARPE-19) cells. The BMs entered ARPE-19 cells by endocytosis after a 6-h incubation and displayed much lower cytotoxicity than chemically synthesized magnetic nanoparticles (MNPs). MNPs exhibited significantly higher genotoxicity than BMs and promoted the expression of Bax (the programmed cell death acceleration protein) and the induction of greater cell necrosis. In BM-treated cells, apoptosis tended to be suppressed via increased expression of the Bcl-2 protein. In conclusion, BMs display excellent biocompatibility and potential for use in the treatment of ocular diseases.
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Affiliation(s)
- Lei Qi
- Institute of Advanced Materials for Nano-Bio Applications, School of Ophthalmology & Optometry, Eye Hospital, Wenzhou Medical University, 270 Xueyuan Xi Road, Wenzhou, Zhejiang 325027, China
| | - Xiujuan Lv
- Institute of Advanced Materials for Nano-Bio Applications, School of Ophthalmology & Optometry, Eye Hospital, Wenzhou Medical University, 270 Xueyuan Xi Road, Wenzhou, Zhejiang 325027, China
| | - Tongwei Zhang
- Biogeomagnetism Group, Paleomagnetism and Geochronology Laboratory, Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
- France-China Bio-Mineralization and Nanostructures Laboratory, Chinese Academy of Sciences, Beijing 100029, China
| | - Peina Jia
- Institute of Advanced Materials for Nano-Bio Applications, School of Ophthalmology & Optometry, Eye Hospital, Wenzhou Medical University, 270 Xueyuan Xi Road, Wenzhou, Zhejiang 325027, China
| | - Ruiying Yan
- Institute of Advanced Materials for Nano-Bio Applications, School of Ophthalmology & Optometry, Eye Hospital, Wenzhou Medical University, 270 Xueyuan Xi Road, Wenzhou, Zhejiang 325027, China
| | - Shuli Li
- Department of Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Ruitao Zou
- Institute of Advanced Materials for Nano-Bio Applications, School of Ophthalmology & Optometry, Eye Hospital, Wenzhou Medical University, 270 Xueyuan Xi Road, Wenzhou, Zhejiang 325027, China
| | - Yuhua Xue
- Institute of Advanced Materials for Nano-Bio Applications, School of Ophthalmology & Optometry, Eye Hospital, Wenzhou Medical University, 270 Xueyuan Xi Road, Wenzhou, Zhejiang 325027, China
| | - Liming Dai
- Institute of Advanced Materials for Nano-Bio Applications, School of Ophthalmology & Optometry, Eye Hospital, Wenzhou Medical University, 270 Xueyuan Xi Road, Wenzhou, Zhejiang 325027, China
- Center of Advanced Science and Engineering for Carbon (Case4Carbon), Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, OH 44106, United States
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13
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Liu X, Ward K, Xavier C, Jann J, Clark AF, Pang IH, Wu H. The novel triterpenoid RTA 408 protects human retinal pigment epithelial cells against H2O2-induced cell injury via NF-E2-related factor 2 (Nrf2) activation. Redox Biol 2015; 8:98-109. [PMID: 26773873 PMCID: PMC4731949 DOI: 10.1016/j.redox.2015.12.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 12/16/2015] [Accepted: 12/16/2015] [Indexed: 01/07/2023] Open
Abstract
Oxidative stress-induced retinal pigment epithelial (RPE) cell damage is an important factor in the pathogenesis of age-related macular degeneration (AMD). Previous studies have shown that RTA 408, a synthetic triterpenoid compound, potently activates Nrf2. This study aimed to investigate the protective effects of RTA 408 in cultured RPE cells during oxidative stress and to determine the effects of RTA 408 on Nrf2 and its downstream target genes. Primary human RPE cells were pretreated with RTA 408 and then incubated in 200μM H2O2 for 6h. Cell viability was measured with the WST-8 assay. Apoptosis was quantitatively measured by annexin V/propidium iodide (PI) double staining and Hoechst 33342 fluorescent staining. Reduced (GSH) and oxidized glutathione (GSSG) were measured using colorimetric assays. Nrf2 activation and its downstream effects on phase II enzymes were examined by Western blot. Treatment of RPE cells with nanomolar ranges (10 and 100nM) of RTA 408 markedly attenuated H2O2-induced viability loss and apoptosis. RTA 408 pretreatment significantly protected cells from oxidative stress-induced GSH loss, GSSG formation and decreased ROS production. RTA 408 activated Nrf2 and increased the expression of its downstream genes, such as HO-1, NQO1, SOD2, catalase, Grx1, and Trx1. Consequently, the enzyme activities of NQO1, Grx1, and Trx1 were fully protected by RTA 408 pretreatment under oxidative stress. Moreover, knockdown of Nrf2 by siRNA significantly reduced the cytoprotective effects of RTA 408. In conclusion, our data suggest that RTA 408 protect primary human RPE cells from oxidative stress-induced damage by activating Nrf2 and its downstream genes.
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Affiliation(s)
- Xiaobin Liu
- Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Keith Ward
- REATA Pharmaceuticals, Inc., Irving, TX, USA
| | - Christy Xavier
- Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Jamieson Jann
- Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Abbot F Clark
- Department of Cell Biology & Immunology, UNTHSC, Ft. Worth, TX, USA; North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Iok-Hou Pang
- Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA; North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Hongli Wu
- Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA; North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, USA; Institute for Cancer Research, University of North Texas Health Science Center, Fort Worth, TX, USA
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14
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Morii T, Ohtsuka K, Ohnishi H, Mochizuki K, Yoshiyama A, Aoyagi T, Hornicek FJ, Ichimura S. BH3 mimetics inhibit growth of chondrosarcoma--a novel targeted-therapy for candidate models. Anticancer Res 2014; 34:6423-6430. [PMID: 25368242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
BACKGROUND Chondrosarcoma is refractory to conventional chemotherapy. BH-3 mimetics ABT-737 and ABT-263 are synthetic small-molecule inhibitors of anti-apoptotic proteins B-cell lymphoma-2 (Bcl2) and Bcl-xL, which play a critical role in survival of chondrosarcoma cells. MATERIALS AND METHODS Chondrosarcoma cell lines SW-1353 and CS-1 were used as the disease model. We used immunoblotting to assess the expression of target molecules Bcl2 and Bcl-xL, and the apoptotic inducers Bcl2-associated X (Bax) and Bcl2-antagonist/killer (Bak). In vitro growth inhibition by BH-3 mimetics was confirmed by photomicroscopic cell counting and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay. Apoptotic induction was confirmed by Enzyme-Linked ImmunoSorbent Assay (ELISA). In vivo growth inhibition was assessed in a non-obese diabetic/severe combined immunodeficient (NOD/SCID) mouse model. RESULTS Expression of the target and effector molecules was confirmed in chondrosarcoma cell lines. BH3 mimetics significantly inhibited cell growth and induced apoptosis in vitro. Administration of ABT-263 inhibited chondrosarcoma growth and improved survival in a mouse model. CONCLUSION BH3 mimetics represent a novel treatment modality for chondrosarcoma.
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Affiliation(s)
- Takeshi Morii
- Department of Orthopaedic Surgery, Faculty of Medicine, Kyorin University, Mitaka, Tokyo, Japan
| | - Kouki Ohtsuka
- Department of Laboratory Medicine, Faculty of Medicine, Kyorin University, Mitaka, Tokyo, Japan
| | - Hiroaki Ohnishi
- Department of Laboratory Medicine, Faculty of Medicine, Kyorin University, Mitaka, Tokyo, Japan
| | - Kazuo Mochizuki
- Department of Orthopaedic Surgery, Faculty of Medicine, Kyorin University, Mitaka, Tokyo, Japan
| | - Akira Yoshiyama
- Department of Orthopaedic Surgery, Faculty of Medicine, Kyorin University, Mitaka, Tokyo, Japan
| | - Takayuki Aoyagi
- Department of Orthopaedic Surgery, Faculty of Medicine, Kyorin University, Mitaka, Tokyo, Japan
| | - Francis J Hornicek
- Center for Sarcoma and Connective Tissue Oncology, Massachusetts General Hospital, Boston, MA, U.S.A
| | - Shoichi Ichimura
- Department of Orthopaedic Surgery, Faculty of Medicine, Kyorin University, Mitaka, Tokyo, Japan
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15
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Zhao C, Qin G, Gao W, Chen J, Liu H, Xi G, Li T, Wu S, Chen T. Potent proapoptotic actions of dihydroartemisinin in gemcitabine-resistant A549 cells. Cell Signal 2014; 26:2223-33. [PMID: 25018064 DOI: 10.1016/j.cellsig.2014.07.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 06/16/2014] [Accepted: 07/04/2014] [Indexed: 11/17/2022]
Abstract
Our recent studies have demonstrated the key roles of reactive oxygen species (ROS)-mediated caspase-8- and Bax-dependent apoptotic pathways in dihydroartemisinin (DHA)-induced apoptosis of A549 cells. This report is designed to investigate the proapoptotic mechanisms of DHA in gemcitabine (Gem)-resistant A549 (A549GR) cells. A549GR cells exhibited lower basal antioxidant capacity, higher level of basal ROS and intracellular Fe(2+) than Gem-sensitive A549 (A549) cells. In contrast to the sluggish ROS generation induced by Gem, DHA induced a rapid ROS generation within 30min. Moreover, Gem induced similar ROS generation in both cell lines, while DHA induced more ROS generation in A549GR cells than in A549 cells. More importantly, after treatment with DHA, A549GR cells showed more potent induction in Bax activation, loss of mitochondrial membrane potential (ΔΨm), caspase activation and apoptosis than A549 cells. Furthermore, NAC pretreatment potently prevented DHA-induced ROS generation and loss of ΔΨm as well as apoptosis, and silencing Bax by shRNA or inhibition of one of caspase-3, -8 and -9 also significantly prevented DHA-induced apoptosis in both cell lines, indicating the key roles of ROS and Bax as well as the caspases. Collectively, DHA presents more potent proapoptotic actions in A549GR cells preferentially over normal A549 cells via ROS-dependent apoptotic pathway, in which Bax and caspases are involved.
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Affiliation(s)
- Chubiao Zhao
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Life Science, South China Normal University, Guangzhou 510631, China
| | - Guiqi Qin
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Life Science, South China Normal University, Guangzhou 510631, China
| | - Weijie Gao
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Life Science, South China Normal University, Guangzhou 510631, China
| | - Jingqin Chen
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Life Science, South China Normal University, Guangzhou 510631, China
| | - Hongyu Liu
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Life Science, South China Normal University, Guangzhou 510631, China
| | - Gaina Xi
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Life Science, South China Normal University, Guangzhou 510631, China
| | - Tan Li
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Life Science, South China Normal University, Guangzhou 510631, China
| | - Shengnan Wu
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Life Science, South China Normal University, Guangzhou 510631, China
| | - Tongsheng Chen
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Life Science, South China Normal University, Guangzhou 510631, China.
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16
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Lee GH, Lee MR, Lee HY, Kim SH, Kim HK, Kim HR, Chae HJ. Eucommia ulmoides cortex, geniposide and aucubin regulate lipotoxicity through the inhibition of lysosomal BAX. PLoS One 2014; 9:e88017. [PMID: 24586300 PMCID: PMC3929538 DOI: 10.1371/journal.pone.0088017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 01/02/2014] [Indexed: 12/11/2022] Open
Abstract
In this study we examined the inhibition of hepatic dyslipidemia by Eucommia ulmoides extract (EUE). Using a screening assay for BAX inhibition we determined that EUE regulates BAX-induced cell death. Among various cell death stimuli tested EUE regulated palmitate-induced cell death, which involves lysosomal BAX translocation. EUE rescued palmitate-induced inhibition of lysosomal V-ATPase, α-galactosidase, α-mannosidase, and acid phosphatase, and this effect was reversed by bafilomycin, a lysosomal V-ATPase inhibitor. The active components of EUE, aucubin and geniposide, showed similar inhibition of palmitate-induced cell death to that of EUE through enhancement of lysosome activity. Consistent with these in vitro findings, EUE inhibited the dyslipidemic condition in a high-fat diet animal model by regulating the lysosomal localization of BAX. This study demonstrates that EUE regulates lipotoxicity through a novel mechanism of enhanced lysosomal activity leading to the regulation of lysosomal BAX activation and cell death. Our findings further indicate that geniposide and aucubin, active components of EUE, may be therapeutic candidates for non-alcoholic fatty liver disease.
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Affiliation(s)
- Geum-Hwa Lee
- Department of Pharmacology and Cardiovascular Research Institute, Medical School, Chonbuk National University, Jeonju, Republic of Korea
| | - Mi-Rin Lee
- Department of Pharmacology and Cardiovascular Research Institute, Medical School, Chonbuk National University, Jeonju, Republic of Korea
| | - Hwa-Young Lee
- Department of Pharmacology and Cardiovascular Research Institute, Medical School, Chonbuk National University, Jeonju, Republic of Korea
| | - Seung Hyun Kim
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Korea
| | - Hye-Kyung Kim
- Department of Pharmacology and Cardiovascular Research Institute, Medical School, Chonbuk National University, Jeonju, Republic of Korea
| | - Hyung-Ryong Kim
- Department of Dental Pharmacology and Wonkwang Dental Research Institute, School of Dentistry, Wonkwang University, Iksan, Republic of Korea
| | - Han-Jung Chae
- Department of Pharmacology and Cardiovascular Research Institute, Medical School, Chonbuk National University, Jeonju, Republic of Korea
- * E-mail:
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Chen K, Shu G, Peng X, Fang J, Cui H, Chen J, Wang F, Chen Z, Zuo Z, Deng J, Geng Y, Lai W. Protective role of sodium selenite on histopathological lesions, decreased T-cell subsets and increased apoptosis of thymus in broilers intoxicated with aflatoxin B₁. Food Chem Toxicol 2013; 59:446-54. [PMID: 23810797 DOI: 10.1016/j.fct.2013.06.032] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 06/16/2013] [Accepted: 06/18/2013] [Indexed: 01/15/2023]
Abstract
For evaluating the ability of selenium (Se) in counteracting the adverse effects of aflatoxin B₁ (AFB₁), two hundred 1-day-old male Avian broilers, divided into five groups, were fed with basal diet (control group), 0.3 mg/kg AFB₁ (AFB₁ group), 0.3 mg/kg AFB₁+0.2 mg/kg Se (+Se group I), 0.3mg/kg AFB₁+0.4 mg/kg Se (+Se group II) and 0.3mg/kg AFB₁+0.6 mg/kg Se (+Se group III), respectively. Compared with control group, the decreased relative weight of thymus and percentages of mature thymocytes, congestion in medulla and much debris in cortex of thymus, and the increased apoptotic thymocytes were observed in AFB1 group. However, supplied dietary sodium selenite could increase the relative weight of thymus and percentages of mature thymocytes, and alleviate histopathological lesions. Compared with AFB1 group, the percentages of apoptotic thymocytes detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling method and flow cytometry method in three +Se groups were decreased, the expression of Caspase-3 and Bax, through quantitative real-time PCR and immunohistochemical method, in three +Se groups were decreased, while the expression of Bcl-2 was increased. The results indicate that sodium selenite supplied in the diet, through a mechanism of apoptosis regulation, may ameliorated AFB₁-induced lesions of thymus and accordingly improve the impaired cellular immune function.
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Affiliation(s)
- Kejie Chen
- Key Laboratory of Animal Diseases and Environmental Hazards of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, Sichuan 625014, China
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18
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Xu HD, Wu D, Gu JH, Ge JB, Wu JC, Han R, Liang ZQ, Qin ZH. The pro-survival role of autophagy depends on Bcl-2 under nutrition stress conditions. PLoS One 2013; 8:e63232. [PMID: 23658815 PMCID: PMC3643928 DOI: 10.1371/journal.pone.0063232] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 04/01/2013] [Indexed: 12/19/2022] Open
Abstract
Autophagy can be induced under nutrition stress conditions. Bcl-2 is a pro-survival protein which inhibits apoptosis and autophagy. However, the role of Bcl-2 in autophagy regulation and cell survival under nutrition deprivation has not been fully understood. This study sought to investigate if Bcl-2 upregulation is essential in limiting autophagic activity and prevent cell death under nutrition deprivation conditions. Autophagic activity was monitored by the changes in GFP-LC3 localization and protein levels of Beclin1, LC3-II, cathepsin D and p62 in neuroblastoma SH-SY5Y cells underwent serum deprivation. Manipulation of Bcl-2 function was achieved with siRNAs and small molecular inhibitors. The cell viability and apoptosis were assessed with MTT assay and Annexin V/PI staining. The results showed that serum starvation increased protein levels of LC3-II and Beclin1 but decreased autophagy substrate p62. Autophagy activation induced by serum deprivation and rapamycin was accompanied by an upregulation of Bcl-2 protein levels. When Bcl-2 was knocked down with siRNA or inhibited with HA 14-1 or ABT-737, serum starvation induced profound cell death and enhanced autophagic flux under nutrition deprivation conditions, while knockdown of autophagic gene Beclin1 or autophagy inhibitors (bafilomycin A1 and E64D), rescued cell death. In contrast, overexpression of Bcl-2 inhibited autophagy and blocked cell death in response to serum deprivation. These data suggest that Bcl-2 plays an essential role in limiting autophagy activation and preventing initiation of programmed cell death. Thus Bcl-2 may be an important mechanism for balancing beneficial and detrimental impacts of autophagy on cell survival.
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Affiliation(s)
- Hai-Dong Xu
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Soochow University School of Pharmaceutical Science, Suzhou, China
| | - Dan Wu
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Soochow University School of Pharmaceutical Science, Suzhou, China
| | - Jin-Hua Gu
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Soochow University School of Pharmaceutical Science, Suzhou, China
| | - Jian-Bin Ge
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Soochow University School of Pharmaceutical Science, Suzhou, China
| | - Jun-Chao Wu
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Soochow University School of Pharmaceutical Science, Suzhou, China
| | - Rong Han
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Soochow University School of Pharmaceutical Science, Suzhou, China
| | - Zhong-Qin Liang
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Soochow University School of Pharmaceutical Science, Suzhou, China
- * E-mail: (ZHQ); (ZQL)
| | - Zheng-Hong Qin
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Soochow University School of Pharmaceutical Science, Suzhou, China
- * E-mail: (ZHQ); (ZQL)
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19
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Zhang A, Hildreth RL, Colberg-Poley AM. Human cytomegalovirus inhibits apoptosis by proteasome-mediated degradation of Bax at endoplasmic reticulum-mitochondrion contacts. J Virol 2013; 87:5657-68. [PMID: 23487455 PMCID: PMC3648137 DOI: 10.1128/jvi.00145-13] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 02/22/2013] [Indexed: 12/30/2022] Open
Abstract
Human cytomegalovirus (HCMV) encodes the UL37 exon 1 protein (pUL37x1), which is the potent viral mitochondrion-localized inhibitor of apoptosis (vMIA), to increase survival of infected cells. HCMV vMIA traffics from the endoplasmic reticulum (ER) to ER subdomains, which are physically linked to mitochondria known as mitochondrion-associated membranes (MAM), and to mitochondria. The antiapoptotic function of vMIA is thought to primarily result from its ability to inhibit Bax-mediated permeabilization of the outer mitochondrial membrane (OMM). Here, we establish that vMIA retargets Bax to the MAM as well as to the OMM from immediate early through late times of infection. However, MAM localization of Bax results in its increased ubiquitination and proteasome-mediated degradation. Surprisingly, HCMV infection does not increase OMM-associated degradation (OMMAD) of Bax, even though the ER and mitochondria are physically connected at the MAM. It was recently found that lipid rafts at the plasma membrane can connect extrinsic and intrinsic apoptotic pathways and can serve as sites of apoptosome assembly. In transfected permissive human fibroblasts, vMIA mediates, through its cholesterol affinity, association of Bax and apoptosome components with MAM lipid rafts. While Bax association with MAM lipid rafts was detected in HCMV-infected cells, association of apoptosome components was not. These results establish that Bax recruitment to the MAM and its MAM-associated degradation (MAMAD) are a newly described antiapoptotic mechanism used by HCMV infection to increase cell survival for its growth.
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Affiliation(s)
- Aiping Zhang
- Research Center for Genetic Medicine, Children's Research Institute, Children's National Medical Center, Washington, DC, USA
| | - Richard L. Hildreth
- Research Center for Genetic Medicine, Children's Research Institute, Children's National Medical Center, Washington, DC, USA
- Molecular Medicine Program,
| | - Anamaris M. Colberg-Poley
- Research Center for Genetic Medicine, Children's Research Institute, Children's National Medical Center, Washington, DC, USA
- Molecular Medicine Program,
- Departments of Integrative Systems Biology,
- Biochemistry and Molecular Biology,
- Pediatrics, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
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20
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Okamoto T, Campbell S, Mehta N, Thibault J, Colman PM, Barry M, Huang DCS, Kvansakul M. Sheeppox virus SPPV14 encodes a Bcl-2-like cell death inhibitor that counters a distinct set of mammalian proapoptotic proteins. J Virol 2012; 86:11501-11. [PMID: 22896610 PMCID: PMC3486325 DOI: 10.1128/jvi.01115-12] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Accepted: 07/24/2012] [Indexed: 12/16/2022] Open
Abstract
Many viruses express inhibitors of programmed cell death (apoptosis), thereby countering host defenses that would otherwise rapidly clear infected cells. To counter this, viruses such as adenoviruses and herpesviruses express recognizable homologs of the mammalian prosurvival protein Bcl-2. In contrast, the majority of poxviruses lack viral Bcl-2 (vBcl-2) homologs that are readily identified by sequence similarities. One such virus, myxoma virus, which is the causative agent of myxomatosis, expresses a virulence factor that is a potent inhibitor of apoptosis. In spite of the scant sequence similarity to Bcl-2, myxoma virus M11L adopts an almost identical 3-dimensional fold. We used M11L as bait in a sequence similarity search for other Bcl-2-like proteins and identified six putative vBcl-2 proteins from poxviruses. Some are potent inhibitors of apoptosis, in particular sheeppox virus SPPV14, which inhibited cell death induced by multiple agents. Importantly, SPPV14 compensated for the loss of antiapoptotic F1L in vaccinia virus and acts to directly counter the cell death mediators Bax and Bak. SPPV14 also engages a unique subset of the death-promoting BH3-only ligands, including Bim, Puma, Bmf, and Hrk. This suggests that SPPV14 may have been selected for specific biological roles as a virulence factor for sheeppox virus.
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Affiliation(s)
- Toru Okamoto
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Stephanie Campbell
- Li Ka Shing Institute for Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Ninad Mehta
- Li Ka Shing Institute for Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - John Thibault
- Li Ka Shing Institute for Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Peter M. Colman
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Michele Barry
- Li Ka Shing Institute for Virology, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - David C. S. Huang
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Marc Kvansakul
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
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21
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Barrasa JI, Santiago-Gómez A, Olmo N, Lizarbe MA, Turnay J. Resistance to butyrate impairs bile acid-induced apoptosis in human colon adenocarcinoma cells via up-regulation of Bcl-2 and inactivation of Bax. Biochim Biophys Acta 2012; 1823:2201-9. [PMID: 22917577 DOI: 10.1016/j.bbamcr.2012.08.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 07/26/2012] [Accepted: 08/09/2012] [Indexed: 12/22/2022]
Abstract
A critical risk factor in colorectal carcinogenesis and tumor therapy is the resistance to the apoptotic effects of different compounds from the intestinal lumen, among them butyrate (main regulator of colonic epithelium homeostasis). Insensitivity to butyrate-induced apoptosis yields resistance to other agents, as bile acids or chemotherapy drugs, allowing the selective growth of malignant cell subpopulations. Here we analyze bile acid-induced apoptosis in a butyrate-resistant human colon adenocarcinoma cell line (BCS-TC2.BR2) to determine the mechanisms that underlay the resistance to these agents in comparison with their parental butyrate-sensitive BCS-TC2 cells. This study demonstrates that DCA and CDCA still induce apoptosis in butyrate-resistant cells through increased ROS production by activation of membrane-associated enzymes and subsequent triggering of the intrinsic mitochondrial apoptotic pathway. Although this mechanism is similar to that described in butyrate-sensitive cells, cell viability is significantly higher in resistant cells. Moreover, butyrate-resistant cells show higher Bcl-2 levels that confer resistance to bile acid-induced apoptosis sequestering Bax and avoiding Bax-dependent pore formation in the mitochondria. We have confirmed that this resistance is reverted using the Bcl-2 inhibitor ABT-263, thus demonstrating that the lower sensitivity of butyrate-resistant cells to the apoptotic effects of bile acids is mainly due to increased Bcl-2 levels.
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Affiliation(s)
- Juan I Barrasa
- Departamento de Bioquímica y Biología Molecular I, Facultad de Ciencias Químicas, Universidad Complutense, 28040-Madrid, Spain
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22
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Abstract
Many viruses, including members of several poxvirus genera, encode inhibitors that block apoptosis by simultaneously binding the proapoptotic Bcl-2 proteins Bak and Bax. The Orthopoxvirus vaccinia virus encodes the Bcl-2-like F1 protein, which sequesters Bak but not Bax. However, N1, a potent virulence factor, is reported to be antiapoptotic and to interact with Bax. Here we investigated whether vaccinia virus inhibits Bak/Bax-dependent apoptosis via the cooperative action of F1 and N1. We found that Western Reserve (WR) and ΔN1L viruses inhibited drug- and infection-induced apoptosis equally. Meanwhile, infections with ΔF1L or ΔN1L/F1L virus resulted in similar levels of Bax activation and apoptosis. Outside the context of infection, N1 did not block drug- or Bax-induced cell death or interact with Bax. In addition to F1 and N1, vaccinia virus encodes further structural homologs of Bcl-2 proteins that are conserved in orthopoxviruses, including A46, A52, B14, C1, C6, C16/B22, K7, and N2. However, we found that these do not associate with Bax or inhibit drug-induced cell death. Based on our findings that N1 is not an antiapoptotic protein, we propose that the F1 orthologs represent the only orthopoxvirus Bcl-2 homolog to directly inhibit the Bak/Bax checkpoint.
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Affiliation(s)
- Antonio Postigo
- Cancer Research UK London Research Institute, London, United Kingdom
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23
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Heaton MB, Paiva M, Kubovic S, Kotler A, Rogozinski J, Swanson E, Madorsky V, Posados M. Differential effects of ethanol on c-jun N-terminal kinase, 14-3-3 proteins, and Bax in postnatal day 4 and postnatal day 7 rat cerebellum. Brain Res 2011; 1432:15-27. [PMID: 22169498 DOI: 10.1016/j.brainres.2011.11.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 11/01/2011] [Accepted: 11/03/2011] [Indexed: 11/18/2022]
Abstract
These studies investigated ethanol effects on upstream cellular elements and interactions which contribute to Bax-related apoptosis in neonatal rat cerebellum at ages of peak ethanol sensitivity (postnatal day 4 [P4]), compared to later ages of relative resistance (P7). Analyses were made of basal levels of the pro-apoptotic c-jun N-terminal kinase (JNK), Bax, and the 14-3-3 anchoring proteins, as well as the responsiveness of these substances to ethanol at P4 versus P7. Dimerization of Bax with 14-3-3 was also investigated at the two ages following ethanol treatment, a process which sequesters Bax in the cytosol, thus inhibiting its mitochondrial translocation and disruption of the mitochondrial membrane potential. Cultured cerebellar granule cells were used to examine the protective potential of JNK inhibition on ethanol-mediated cell death. Basal levels of JNK were significantly higher at P4 than P7, but no differences in the other proteins were found. Activated JNK, and cytosolic and mitochondrially-translocated Bax were increased in P4 but not P7 animals following ethanol exposure, while protective 14-3-3 proteins were increased only at P7. Ethanol treatment resulted in decreases in Bax:14-3-3 heterodimers at P4, but not at P7. Inhibition of JNK activity in vitro provided partial protection against ethanol neurotoxicity. Thus, differential temporal vulnerability to ethanol in this CNS region correlates with differences in both levels of apoptosis-related substances (e.g., JNK), and differential cellular responsiveness, favoring apoptosis at the most sensitive age and survival at the resistant age. The upstream elements contributing to this vulnerability can be targets for future therapeutic strategies.
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Affiliation(s)
- Marieta Barrow Heaton
- Department of Neuroscience, University of Florida College of Medicine, USA; McKnight Brain Institute, USA.
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24
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Cheng G, Xie L. Parthenolide induces apoptosis and cell cycle arrest of human 5637 bladder cancer cells in vitro. Molecules 2011; 16:6758-68. [PMID: 21829151 PMCID: PMC6264178 DOI: 10.3390/molecules16086758] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 07/30/2011] [Accepted: 08/02/2011] [Indexed: 12/17/2022] Open
Abstract
Parthenolide, the principal component of sesquiterpene lactones present in medical plants such as feverfew (Tanacetum parthenium), has been reported to have anti-tumor activity. In this study, we evaluated the therapeutic potential of parthenolide against bladder cancer and its mechanism of action. Treatment of bladder cancer cells with parthenolide resulted in a significant decrease in cell viability. Parthenolide induced apoptosis through the modulation of Bcl-2 family proteins and poly (ADP-ribose) polymerase degradation. Treatment with parthenolide led to G1 phase cell cycle arrest in 5637 cells by modulation of cyclin D1 and phosphorylated cyclin-dependent kinase 2. Parthenolide also inhibited the invasive ability of bladder cancer cells. These findings suggest that parthenolide could be a novel therapeutic agent for treatment of bladder cancer.
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Affiliation(s)
| | - Liping Xie
- Author to whom correspondence should be addressed; ; Tel: +86-571-87236735; Fax: +86-571-87072577
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25
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Liu Y, Ma S, Qu R. SCLM, total saponins extracted from Chaihu-jia-longgu-muli-tang, reduces chronic mild stress-induced apoptosis in the hippocampus in mice. Pharm Biol 2010; 48:840-848. [PMID: 20673169 DOI: 10.3109/13880200903296154] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Increasing evidence demonstrates that stress or depression can lead to atrophy and cell loss in the hippocampus. In contrast, antidepressant treatment significantly reduces apoptosis in the dentate granule cell layer and subgranular zone in animal models of depression. In the present study, we investigated the neuroprotective action of SCLM, the total saponins extracted from Chaihu-jia-longgu-muli-tang, a traditional Chinese medicinal formula which was prescribed 1000 years ago, in the reduction of apoptosis in hippocampal neurons using an experimental chronic mild stress (CMS) model. Mice were subjected to the CMS procedure for a period of 21 consecutive days. SCLM (100 mg/kg, p.o.) or fluoxetine (20 mg/ kg, p.o.) was administered during the stress periods. CMS mice showed a decreased sucrose intake over 21 days, and an increase in the number of TUNEL-positive neurons as well as up-regulation of the apoptotic-related factors, such as Bax and caspase-3 in the hippocampus, compared with control mice. On the other hand, the administration of SCLM (100 mg/kg) and fluoxetine (20 mg/kg) reversed these effects induced by CMS, showing a significant increase of sucrose intake and a dramatic reduction of TUNEL-positive neurons and decreased expression of Bax and caspase-3 proteins. The present results suggest that SCLM possesses a significant antidepressant-like property, and this effect may be through protection against stress-induced neuronal apoptosis by affecting the expression of Bax and caspase-3 proteins in the hippocampus. These findings provide important information that the anti-apoptotic effect of herbal medicine therapy may be beneficial for the treatment of depression.
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Affiliation(s)
- Yadong Liu
- Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, People's Republic of China
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26
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Huang ST, Wang CY, Yang RC, Chu CJ, Wu HT, Pang JHS. Wogonin, an active compound in Scutellaria baicalensis, induces apoptosis and reduces telomerase activity in the HL-60 leukemia cells. Phytomedicine 2010; 17:47-54. [PMID: 19577445 DOI: 10.1016/j.phymed.2009.06.005] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Revised: 05/21/2009] [Accepted: 06/02/2009] [Indexed: 05/28/2023]
Abstract
Crude extract of Scutellaria baicalensis (S. baicalensis) has cytotoxic effect on human myelogenous leukemia cells (HL-60). We invesigated which compound from the crude extract is responsible for the cytotoxic effect on HL-60 cells. We identified 29 compounds from the crude extract using high performance liquid chromatography mass spectrometry (HPLC/MS). Two of the compounds, baicalin and wogonoside, are converted to baicalein and wogonin, respectively, after treatment with beta-glucuronidase. We observed a dose-dependent reduction in cell viability when cells with either wogonin or aqueous extract of S. baicalensis. Several of the apoptotic features including deoxyribonucleic acid (DNA) fragmentation and increased caspase-3 activity were found in cells treated with wogonin and aqueous extract. The changes were associated with down-regulation of Bcl-2, and not Bax. Furthermore, treatment of HL-60 cells with wogonin or S. baicalensis led to the inhibition of human telomerase reverse transcriptase (hTERT), human telomerase-associated protein 1 (hTP1) and c-myc messenger ribonucleic acid (m-RNA) expression. Wogonin and S. baicaleisis down-regulated the telomerase activity. Our findings suggest that wogonin may be the major compound in S. baicalensis responsible for HL-60 growth inhibition in vitro. The inhibition of HL-60 cell growth is mediated partly through the induction of Bax/Bcl-2 apoptosis and by telomerase inhibition through suppression of c-myc, which is a promoter of hTERT.
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Affiliation(s)
- Sheng-Teng Huang
- Department of Chinese Medicine, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Taiwan.
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27
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Zhang QL, Niu Q, Niu PY, Shi YT, Liu CY, Di Gioacchino M, Zhang L, Zhang C, Braga M. Bax gene silencing: a potential intervention in aluminum-induced neural cell death. J BIOL REG HOMEOS AG 2010; 24:7-17. [PMID: 20385067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
There is a vast amount of evidence indicating that Bax plays a major role in the development, maintenance, and survival of neurons and neuron-supporting cells such as glial cells. The high potency of Bax small interfering RNA (siRNA), as shown by many experimental studies, makes it a rational candidate as a co-therapeutic agent in apoptotic cell death. To investigate whether Bax RNA interference (RNAi) may serve as a potential intervention in neural cell death induced by aluminum, we herein established aluminum (Al)-treated gliatoma (C6) cells as a model for evaluating neurotoxic injury on normal glia. Using the cell model, we undertook a different approach by inducing glial cell death with Al and then using Bax gene RNAi to suppress glial cell death. Combining cell viability assays and expression analyses by quantitative real-time PCR (qRT-PCR) and immunocytochemistry, we selected and validated the optimal siRNA from 3 candidate siRNAs for the Bax gene. Sequenced reduction of neural cell death was determined with flow cytometry. Our data identified siRNA1 as the most effective siRNA. The optimal concentration of the transfection agent was 20 nM and the optimal incubation period was 72 h. The transfection and knockdown efficiencies were 95 percent and 62 percent, respectively, which closely correlated with Bax protein expression and also the cell apoptosis intervention. Taken together, Bax is essential for apoptosis induced by aluminum. Inactivation of the Bax gene could be an effective strategy for delaying the onset of apoptosis induced by Al. Our results reveal promising therapeutic potential for Bax gene silencing in Al-induced neurodegeneration.
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Affiliation(s)
- Q L Zhang
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan, China
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28
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Tonnesen MF, Grunnet LG, Friberg J, Cardozo AK, Billestrup N, Eizirik DL, Størling J, Mandrup-Poulsen T. Inhibition of nuclear factor-kappaB or Bax prevents endoplasmic reticulum stress- but not nitric oxide-mediated apoptosis in INS-1E cells. Endocrinology 2009; 150:4094-103. [PMID: 19556421 DOI: 10.1210/en.2009-0029] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Accumulating evidence suggests that endoplasmic reticulum (ER) stress by mechanisms that include ER Ca(2+) depletion via NO-dependent down-regulation of sarcoendoplasmic reticulum Ca(2+) ATPase 2b (SERCA2b) contributes to beta-cell death in type 1 diabetes. To clarify whether the molecular pathways elicited by NO and ER Ca(2+) depletion differ, we here compare the direct effects of NO, in the form of the NO donor S-nitroso-N-acetyl-D,L-penicillamine (SNAP), with the effects of SERCA2 inhibitor thapsigargin (TG) on MAPK, nuclear factor kappaB (NFkappaB), Bcl-2 proteins, ER stress, and apoptosis. Exposure of INS-1E cells to TG or SNAP caused caspase-3 cleavage and apoptosis. Both TG and SNAP induced activation of the proapoptotic transcription factor CCAAT/enhancer-binding protein homologous protein (CHOP). However, other classical ER stress-induced markers such as up-regulation of ER chaperone Bip and alternative splicing of the transcription factor Xbp-1 were exclusively activated by TG. TG exposure caused NFkappaB activation, as assessed by IkappaB degradation and NFkappaB DNA binding. Inhibition of NFkappaB or the Bcl-2 family member Bax pathways protected beta-cells against TG- but not SNAP-induced beta-cell death. These data suggest that NO generation and direct SERCA2 inhibition cause two quantitative and qualitative different forms of ER stress. In contrast to NO, direct ER stress induced by SERCA inhibition causes activation of ER stress signaling pathways and elicit proapoptotic signaling via NFkappaB and Bax.
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29
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Kizildag S, Ates H, Kizildag S. Treatment of K562 cells with 1,25-dihydroxyvitamin D3 induces distinct alterations in the expression of apoptosis-related genes BCL2, BAX, BCLXL, and p21. Ann Hematol 2009; 89:1-7. [PMID: 19475409 DOI: 10.1007/s00277-009-0766-y] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Accepted: 05/18/2009] [Indexed: 11/26/2022]
Abstract
Apoptosis, or programmed cell death, is a very important phenomenon in cytotoxicity induced by anticancer treatment. 1α,25-Dihydroxyvitamin D(3) (1,25-(OH)(2)D(3)), the active metabolite of vitamin D, inhibits the growth of multiple types of cancer cells including breast, colon, and prostate cancer cell lines. We studied alterations in the mRNA expression levels of BCL2, BAX, CYC, BCL-XL, and VDR genes in the K562 chronic myeloid leukemia cell line in response to treatment with 1,25-(OH)(2)D(3). Morphological observation of K562 cells was evaluated by the staining with Wright's solution. Cell percentage at different phases of the cell cycle was measured, and apoptosis was measured by flow cytometry. The expression levels of the apoptosis-related genes were analyzed by real-time reverse transcription polymerase chain reaction. We found that treatment with 1,25-(OH)(2)D(3) down-regulates BCL2 and BCL-XL mRNA expressions, as well as up-regulates expressions of BAX and p21 mRNA. The expression pattern of CYC and VDR genes were not influenced. However, K562 cells treated with 1,25-(OH)(2)D(3) caused an arrest of cell cycle progression in G1 phase resulting in a decreased number of cells in the S phase, complemented by an accumulation of cells in the G0-G1 phases. Our data show the modulatory effects of 1,25-(OH)(2)D(3) treatment in apoptosis-related genes in K562 cells.
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Affiliation(s)
- Sefa Kizildag
- Department of Medical Biology and Medical Genetics, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.
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30
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Mousavi SH, Tavakkol-Afshari J, Brook A, Jafari-Anarkooli I. Role of caspases and Bax protein in saffron-induced apoptosis in MCF-7 cells. Food Chem Toxicol 2009; 47:1909-13. [PMID: 19457443 DOI: 10.1016/j.fct.2009.05.017] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Revised: 04/14/2009] [Accepted: 05/07/2009] [Indexed: 11/17/2022]
Abstract
Saffron (Crocus sativus), widely used as a spice in Middle Eastern cuisine and is known for anti-cancer properties. The mechanism of saffron-induced cytotoxicity, in tumor cells has not been adequately explored. Therefore, we investigated the role of caspases and Bax protein in saffron-induced apoptosis in MCF-7 cells, a commonly used cell culture system for in vitro studies on breast cancer. Cells were incubated with different concentrations of saffron extract. Cell viability was quantitated by MTT assay. Apoptotic cells were determined using PI staining of DNA fragmentation by flow cytometry (sub-G1 peak). Role of caspase were studied using the pan-caspase inhibitor. Bax protein expression was analysed by western blotting. Saffron extract (200-2000 microg/ml) decreased cell viability in MCF-7 cells as a concentration- and time-dependent manner with an IC50 of 400+/-18.5 microg/ml after 48 h. Analysis of DNA fragmentation by flow cytometry showed apoptotic cell death in MCF-7 cell treated with saffron extract. Saffron-induced apoptosis could be inhibited by pan-caspase inhibitors, indicating caspase-dependent pathway was induced by saffron in MCF-7 cells. Bax protein expression was also increased in saffron-treated cells. Thus saffron exerts proapoptotic effects in a breast cancer-derived cell line and could be considered as a potential chemotherapeutic agent in breast cancer.
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Affiliation(s)
- Seyed Hadi Mousavi
- Department of Pharmacology and Pharmacological Research Centre of Medicinal Plants, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
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Yu J, Khaoustov V, Xu Y, Yoffe B. [Epicatechin abolished TDCA-induced apoptosis in Huh7 cell by inhibiting Bax, p38 MAPK and ROS production]. Zhongguo Zhong Yao Za Zhi 2009; 34:1272-1275. [PMID: 19673394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
OBJECTIVE To investigate the molecular mechanisms involved in anti-apoptotic effects of epicathechin in liver cells. METHOD Human hepatoma cell line (Huh7) was treated with 400 miromol x L(-1) taurodeoxycholic acid (TDCA) for 48 hours to induce apoptosis. Intracellular generation of reactive oxygen species (ROS) was detected with DCFH-DA assay. Caspase-3/7 activity was analyzed with EnzoLyte Homogeneous AMC kit. Cell proliferation was measured by MTT assay. The expression of Bax, Phospho-p38 MAPK and the levels of cytochrome C were assessed by Western-blot analysis. RESULT TDCA-dependent intracellular ROS production was 8-fold higher as compared to untreated cells, consequently resulting in 45% reduction of cell viability. Interestingly, pretreatment of cells with epicatechin resulted in a dose-dependent inhibition of TDCA-induced ROS generation and reduced cell apoptosis by threefold as compared to TDCA treatment alone. In addition epicatechin reduced Bax expression with consequential inhibition of cytochrome C release from mitochondria, inhibition of caspase 3/7 activation and p38 MAPK phosphorylation. CONCLUSION Epicatechin protects Huh7 cells from oxidative stress and mitochondria-induced apoptosis. The molecular mechanisms of anti-apoptotic effects of epicatechin were associated with inhibition of p38 MAPK phosphorylation and Bax expression, and reduction of ROS production. These findings implicate epicathechin might have potential as protective agent against a variety of oxidative stress-mediated liver conditions.
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Affiliation(s)
- Jing Yu
- Hepatology Department, the First Affiliated Hospital of Guangxi Chinese Medical University, Nanning 530023, China.
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Wang X, Zhao J, Tang S, Lee S, Glazer RI, Hewlett I. c-FLIPL regulates PKC via AP-2 to inhibit Bax-mediated apoptosis induced by HIV-1 gp120 in Jurkat cells. Mol Cell Biochem 2009; 330:23-9. [PMID: 19363595 DOI: 10.1007/s11010-009-0096-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Accepted: 03/30/2009] [Indexed: 01/10/2023]
Abstract
c-FLIPL, an inhibitor of caspase 8, is known to inhibit the Fas/caspase 8 apoptotic pathway; however, its involvement of Bax/mitochondrial apoptosis is not well understood. Using human cells, Jurkat cell line, induced with HIV-1 gp120, we studied the effects of c-FLIPL on Bax/mitochondrial apoptosis. We found that the induction of apoptosis by HIV-1 envelope protein, gp120, involved the activation of both Bax-dependent and death receptor-mediated pathways, and HIV-1 infection deceased c-FLIPL expression. Interestingly, c-FLIPL expression downregulated protein kinase C (PKC) expression at the transcript level involving activated protein-2 (AP-2). c-FLIPL expression reduced AP-2 protein levels required to promote PKC protein expression and PKC-associated inactive form of Bax, and inhibited Bax activation, suggesting that c-FLIPL inhibits Bax activation via modulating PKC expression at the transcriptional level involving AP-2 during gp120 treatment. Collectively, these findings further corroborate the concept that gp120 plays an important role, via involvement of molecules such as c-FLIPL, in apoptotic cell death due to HIV-1 infection.
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Affiliation(s)
- Xue Wang
- Laboratory of Molecular Virology, Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Building 29B, Rm 4NN16, 8800 Rockville Pike, Bethesda, MD, 20892, USA.
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Abstract
Insulin resistance is a primary characteristic of type 2 diabetes. Several lines of evidence suggest that accumulation of free fatty acids in skeletal muscle may at least in part contribute to insulin resistance and may be linked to mitochondrial dysfunction, leading to apoptosis. Palmitate treatment of several cell lines in vitro results in apoptosis and inhibits protein kinase B (Akt) activity in response to insulin. However, the role of Bax and Bcl-2 in regulating palmitate-induced apoptosis has not been well studied. Therefore, the purpose of this study was to determine whether palmitate-induced apoptosis in C(2)C(12) myotubes is dependent on Bax to Bcl-2 binding. An additional purpose of this study was to determine whether the changes in Bax to Bcl-2 binding corresponded to decreases in Akt signaling in palmitate-treated myoblasts. Apoptotic signaling proteins were examined in C(2)C(12) myotubes treated overnight with palmitate. Bax to Bcl-2 binding was determined through a coimmunoprecipitation assay that was performed in myotubes after 2 h of serum starvation, followed by 10 min of serum reintroduction. This experiment evaluated whether temporal Akt activity coincided with Bax to Bcl-2 binding. Last, the contribution of Bax to palmitate-induced apoptosis was determined by treatment with Bax siRNA. Palmitate treatment increased apoptosis in C(2)C(12) myotubes as shown by a twofold increase in DNA fragmentation, an approximately fivefold increase in caspase-3 activity, and a 2.5-fold increase in caspase-9 activity. Palmitate treatment significantly reduced Akt protein expression and Akt activity. In addition, there was a fourfold reduction in Bax to Bcl-2 binding with palmitate treatment, which mirrored the reduction in Akt(Ser473) phosphorylation. Furthermore, treatment of the C(2)C(12) myotubes with Bax siRNA attenuated the apoptotic effects of palmitate treatment. These data show that palmitate induces Bax-mediated apoptosis in C(2)C(12) myotubes and that this effect corresponds to reductions in Akt(Ser473) phosphorylation.
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Jurak I, Schumacher U, Simic H, Voigt S, Brune W. Murine cytomegalovirus m38.5 protein inhibits Bax-mediated cell death. J Virol 2008; 82:4812-22. [PMID: 18321965 PMCID: PMC2346748 DOI: 10.1128/jvi.02570-07] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Accepted: 02/27/2008] [Indexed: 11/20/2022] Open
Abstract
Many viruses encode proteins that inhibit the induction of programmed cell death at the mitochondrial checkpoint. Murine cytomegalovirus (MCMV) encodes the m38.5 protein, which localizes to mitochondria and protects human HeLa cells and fibroblasts from apoptosis triggered by proteasome inhibitors but not from Fas-induced apoptosis. However, the ability of this protein to suppress the apoptosis of murine cells and its role during MCMV infection have not been investigated previously. Here we show that m38.5 is expressed at early time points during MCMV infection. Cells infected with MCMVs lacking m38.5 showed increased sensitivity to cell death induced by staurosporine, MG132, or the viral infection itself compared to the sensitivity of cells infected with wild-type MCMV. This defect was eliminated when an m38.5 or Bcl-X(L) gene was inserted into the genome of a deletion mutant. Using fibroblasts deficient in the proapoptotic Bcl-2 family proteins Bak and/or Bax, we further demonstrated that m38.5 protected from Bax- but not Bak-mediated apoptosis and interacted with Bax in infected cells. These results consolidate the role of m38.5 as a viral mitochondrion-localized inhibitor of apoptosis and its functional similarity to the human cytomegalovirus UL37x1 gene product. Although the m38.5 gene is not homologous to the UL37x1 gene at the sequence level, m38.5 is conserved among rodent cytomegaloviruses. Moreover, the fact that MCMV-infected cells are protected from both Bak- and Bax-mediated cell death suggests that MCMV possesses an additional, as-yet-unidentified mechanism to block Bak-mediated apoptosis.
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Affiliation(s)
- Igor Jurak
- Division of Viral Infections, Robert Koch Institute, Nordufer 20, 13353 Berlin, Germany
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35
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Gomez JA, Gama V, Yoshida T, Sun W, Hayes P, Leskov K, Boothman D, Matsuyama S. Bax-inhibiting peptides derived from Ku70 and cell-penetrating pentapeptides. Biochem Soc Trans 2007; 35:797-801. [PMID: 17635151 DOI: 10.1042/bst0350797] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We found that Ku70, a known DNA repair factor, has a novel function to bind and inhibit Bax (Bcl-2-associated X protein), a key mediator of apoptosis. Pentapeptides derived from the Bax-binding domain of Ku70 were cell-permeable and protected cells from Bax-mediated apoptosis. These pentapeptides were called BIPs (Bax-inhibiting peptides). BIPs may become a useful therapeutic tool to reduce cellular damage. We also generated BIP mutant pentapeptides that do not inhibit Bax, but retain their cell-penetrating activity. Since both BIPs and BIP mutants are cell-permeable, these peptides were designated CPP5s (cell-penetrating pentapeptides). Among the CPP5s discovered, VPTLK (BIP) and KLPVM (BIP mutant) were confirmed to possess protein transduction activity by examination of the delivery of GFP (green fluorescent protein) into cells by these peptides. The mechanism of cell penetration by CPP5s is not known. CPP5s enter the cell at 0 and 4 degrees C. In preliminary studies, various inhibitors of endocytosis and pinocytosis did not show any significant suppression of CPP5 cell entry. CPP5s have very low toxicity in vitro and in vivo and so may be useful tools in order to develop non-toxic drug-delivery technologies.
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Affiliation(s)
- J A Gomez
- Pharmacology Department, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
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36
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Caruso C, Durand D, Schiöth HB, Rey R, Seilicovich A, Lasaga M. Activation of melanocortin 4 receptors reduces the inflammatory response and prevents apoptosis induced by lipopolysaccharide and interferon-gamma in astrocytes. Endocrinology 2007; 148:4918-26. [PMID: 17595227 DOI: 10.1210/en.2007-0366] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Alpha-MSH exerts an immunomodulatory action in the brain and may play a neuroprotective role acting through melanocortin 4 receptors (MC4Rs). In the present study, we show that MC4Rs are constitutively expressed in astrocytes as determined by immunocytochemistry, RT-PCR, and Western blot analysis. alpha-MSH (5 microm) reduced the nitric oxide production and the expression of inducible nitric oxide synthase (iNOS) induced by bacterial lipopolysaccharide (LPS, 1 microg/ml) plus interferon-gamma (IFN-gamma, 50 ng/ml) in cultured astrocytes after 24 h. alpha-MSH also attenuated the stimulatory effect of LPS/IFN-gamma on prostaglandin E(2) release and cyclooxygenase-2 (COX-2) expression. Treatment with HS024, a selective MC4R antagonist, blocked the antiinflammatory effects of alpha-MSH, suggesting a MC4R-mediated mechanism in the action of this melanocortin. In astrocytes, LPS/IFN-gamma treatment reduced cell viability, increased the number of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive cells and activated caspase-3. alpha-MSH prevented these apoptotic events, and this cytoprotective effect was abolished by HS024. LPS/IFN-gamma decreased Bcl-2, whereas it increased Bax protein expression in astrocytes, thus increasing the Bax/Bcl-2 ratio. Alpha-MSH produced a shift in Bax/Bcl-2 ratio toward astrocyte survival because it increased Bcl-2 expression and also prevented the effect of LPS/IFN-gamma on Bax and Bcl-2 expression. In summary, these findings suggest that alpha-MSH, through MC4R activation, attenuates LPS/IFN-gamma-induced inflammation by decreasing iNOS and COX-2 expression and prevents LPS/IFN-gamma-induced apoptosis of astrocytes by modulating the expression of proteins of the Bcl-2 family.
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Affiliation(s)
- Carla Caruso
- Centro de Investigaciones en Reproducción, School of Medicine, University of Buenos Aires, Buenos Aires 1121ABG, Argentina
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37
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Li Y, Yokota T, Gama V, Yoshida T, Gomez JA, Ishikawa K, Sasaguri H, Cohen HY, Sinclair DA, Mizusawa H, Matsuyama S. Bax-inhibiting peptide protects cells from polyglutamine toxicity caused by Ku70 acetylation. Cell Death Differ 2007; 14:2058-67. [PMID: 17885668 DOI: 10.1038/sj.cdd.4402219] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Polyglutamine (polyQ) diseases, such as Huntington's disease and Machado-Joseph disease (MJD), are caused by gain of toxic function of abnormally expanded polyQ tracts. Here, we show that expanded polyQ of ataxin-3 (Q79C), a gene that causes MJD, stimulates Ku70 acetylation, which in turn dissociates the proapoptotic protein Bax from Ku70, thereby promoting Bax activation and subsequent cell death. The Q79C-induced cell death was significantly blocked by Ku70 or Bax-inhibiting peptides (BIPs) designed from Ku70. Furthermore, expression of SIRT1 deacetylase and the addition of a SIRT1 agonist, resveratrol, reduced Q79C toxicity. In contrast, mimicking acetylation of Ku70 abolished the ability of Ku70 to suppress Q79C toxicity. These results indicate that Bax and Ku70 acetylation play important roles in Q79C-induced cell death, and that BIP may be useful in the development of therapeutics for polyQ diseases.
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Affiliation(s)
- Y Li
- Department of Neurology and Neurological Science, Tokyo Medical and Dental University, Tokyo, Japan
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38
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Yamasaki S, Maeda M, Ohshima K, Kikuchi M, Otsuka T, Harada M. Growth and apoptosis of human natural killer cell neoplasms: role of interleukin-2/15 signaling. Leuk Res 2007; 28:1023-31. [PMID: 15289013 DOI: 10.1016/j.leukres.2004.02.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2003] [Accepted: 02/23/2004] [Indexed: 01/16/2023]
Abstract
Interleukin (IL)-15 plays an important role in the survival of human natural killer (NK) cells. We investigated IL-2/15 signaling in NK cell neoplasms from five patients and in five cell lines (NK-92, KHYG-1, SNK-6, HANK1 and MOTN-1) compared to mature peripheral NK cells from 10 healthy subjects. Apoptosis of NK cell lines was prevented by addition of IL-15 in vitro. Blocking IL-2/15Rbeta on IL-2-stimulated NK-92 cells resulted in reduced expression of Bcl-X(L) and phosphorylated Stat5, which paralleled early apoptosis without altering Bcl-2 expression. These data add IL-2/15Rbeta to the list of factors important for the survival of NK cell neoplasms.
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Affiliation(s)
- Satoshi Yamasaki
- Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Fukuoka, Japan.
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Liu HM, Li JX, Chen LB. Ischemic preconditioning relieves ischemia/reperfusion injury of hippocampus neurons in rat by inhibiting p53 and bax expressions. Chin Med Sci J 2007; 22:123-7. [PMID: 17763586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
OBJECTIVE To examine whether ischemic preconditioning (IPC) can protect neuron against delayed death in CA1 subfield of hippocampus following reperfusion of a lethal ischemia in rats, and explore the role of p53 and bax in this process. METHODS We examined the effect of IPC on delayed neuron death, neuron apoptosis, expressions of p53 and bax gene in the CA1 area of hippocampus in the rats using HE staining, flow cytometry, RT-PCR, and immunohistochemistry technique. RESULTS IPC enhanced the quantity of survival cells in the CA1 region of hippocampus (216 +/- 9 cells/0.72 mm2 vs. 30 +/- 5 cells/0.72 mm2, P < 0.01) , decreased the percentages of apoptotic neurons of hippocampus caused by ischemia/reperfusion (2.06% +/- 0.21% vs. 4.27% +/- 0.08%, P < 0.01 ), and weakened the expressions of p53 and bax gene of hippocampus compared with ischemia/reperfusion without IPC. CONCLUSION IPC can protect the neurons in the CA1 region of hippocampus against apoptosis caused by ischemia/reperfusion, and this process may be related to the reduced expressions of p53 and bax.
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Affiliation(s)
- Hui-Min Liu
- Institute of Physiology, School of Medicine, Shandong University, Jinan 250012
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40
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Chen C, Chang YC, Liu CL, Liu TP, Chang KJ, Guo IC. Leptin induces proliferation and anti-apoptosis in human hepatocarcinoma cells by up-regulating cyclin D1 and down-regulating Bax via a Janus kinase 2-linked pathway. Endocr Relat Cancer 2007; 14:513-29. [PMID: 17639064 DOI: 10.1677/erc-06-0027] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Obesity serves as an important risk factor for incidences of both cirrhotic and non-cirrhotic hepatocellular carcinoma (HCC), which is the third leading cause of cancer death worldwide. Leptin, the obesity biomarker molecule secreted systemically by body fat mass and locally by activated hepatic stellate cells, is proposed to play a certain role in HCC growth. Here, we show both proliferative and anti-apoptotic effects of leptin in HCC cells. Leptin stimulated cyclin D1 promoter activity to increase cyclin D1 protein expression, which accelerated the cell cycle progression. The reduced ratio between anti-apoptotic (Bcl-2) and pro-apoptotic (Bax) Bcl-2 family proteins by transforming growth factor (TGF)-beta 1 caused HCC cells degradation of poly(ADP-ribose) polymerase and consequential apoptosis; whereas, leptin protected cells from apoptosis by reversing TGF-beta 1-reduced Bcl-2/Bax ratio as a result of down-regulating Bax. Any inhibitor specific for Janus kinase 2 (JAK2), phosphatidylinositol 3-kinase (PI3K)/Akt, or mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase 1/2 (ERK1/2) blocked these leptin functions. When intrahepatocytic JAK2 was activated by leptin, the active JAK2 afterward triggered a signaling cascade involving activations of PI3K/Akt and MEK/ERK1/2 in order of occurrence. As yet, in most cases, the crosstalks among signaling pathways primarily studied in diverse cancer cell types for mediating somatotropic effect of leptin are not well clarified and seem to be cell-type dependent. For the first time, our results demonstrate the direct effects of leptin on HCC growth and define its signal pathway with a crosstalking JAK2-PI3K/Akt-MEK/ERK1/2 connection. The identified hierarchy of intrahepatocytic leptin signaling pathway provides a clear basis potentially beneficial to make accurate and effectual strategies for facing both cirrhotic and non-cirrhotic liver carcinogenesis.
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Affiliation(s)
- Chiachen Chen
- Department of Veterinary Medicine, College of Bio-Resources and Agriculture National Taiwan University, 10617 Taipei, Taiwan, ROC
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41
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Wang X, Wang Y, Kim HP, Choi AMK, Ryter SW. FLIP inhibits endothelial cell apoptosis during hyperoxia by suppressing Bax. Free Radic Biol Med 2007; 42:1599-609. [PMID: 17448907 DOI: 10.1016/j.freeradbiomed.2007.02.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2006] [Revised: 02/16/2007] [Accepted: 02/20/2007] [Indexed: 02/08/2023]
Abstract
High oxygen tension (hyperoxia) causes pulmonary cell death, involving apoptosis, necrosis, or mixed death phenotypes, though the underlying mechanisms remain unclear. In mouse lung endothelial cells (MLEC) hyperoxia activates both extrinsic (Fas-dependent) and intrinsic (mitochondria-dependent) apoptotic pathways. We examined the hypothesis that FLIP, an inhibitor of caspase-8, can protect endothelial cells against the lethal effects of hyperoxia. Hyperoxia caused the time-dependent downregulation of FLIP in MLEC. Overexpression of FLIP attenuated intracellular reactive oxygen species generation during hyperoxia exposure, by downregulating extracellular-regulated kinase-1/2 activation and p47(phox) expression. FLIP prevented hyperoxia-induced trafficking of the death-inducing signal complex from the Golgi apparatus to the plasma membrane. Furthermore, FLIP blocked the activations of caspase-8/Bid, caspases -3/-9, and inhibited the mitochondrial translocation and activation of Bax, resulting in protection against hyperoxia-induced cell death. Under normoxic conditions, FLIP expression increased the phosphorylation of p38 mitogen-activated protein kinase leading to increased phosphorylation of Bax during hyperoxic stress. Furthermore, FLIP expression markedly inhibited protein kinase C activation and expression of distinct protein kinase C isoforms (alpha, eta, and zeta), and stabilized an interaction of PKC with Bax. In conclusion, FLIP exerted novel inhibitory effects on extrinsic and intrinsic apoptotic pathways, which significantly protected endothelial cells from the lethal effects of hyperoxia.
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Affiliation(s)
- Xue Wang
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh Medical Center, 3459 Fifth Avenue, MUH 628NW, Pittsburgh, PA 15213, USA
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42
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Pauleau AL, Larochette N, Giordanetto F, Scholz SR, Poncet D, Zamzami N, Goldmacher VS, Kroemer G. Structure-function analysis of the interaction between Bax and the cytomegalovirus-encoded protein vMIA. Oncogene 2007; 26:7067-80. [PMID: 17496930 DOI: 10.1038/sj.onc.1210511] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The viral mitochondrial inhibitor of apoptosis (vMIA) encoded by the human cytomegalovirus exerts cytopathic effects and neutralizes the proapoptotic endogenous Bcl-2 family member Bax by recruiting it to mitochondria, inducing its oligomerization and membrane insertion. Using a combination of computational modeling and mutational analyses, we addressed the structure-function relationship of the molecular interaction between the protein Bax and the viral antiapoptotic protein vMIA. We propose a model in which vMIA exhibits an overall fold similar to Bcl-X(L). In contrast to Bcl-X(L), however, this predicted conformation of vMIA does not bind to the BH3 domain of Bax and rather engages in electrostatic interactions that involve a stretch of amino acids between the BH3 and BH2 domains of Bax and an alpha-helical domain located within the previously defined Bax-binding domain of vMIA, between the putative BH1-like and BH2-like domains. According to this model, vMIA is likely to bind Bax preferentially in its membrane-inserted conformation. The capacity of vMIA to cause fragmentation of the mitochondrial network and disorganization of the actin cytoskeleton is independent of its Bax-binding function. We found that Delta131-147 vMIA mutant, which lacks both the Bax-binding function and cell-death suppression but has intact mitochondria-targeting capacity, is similar to vMIA in its ability to disrupt the mitochondrial network and to disorganize the actin cytoskeleton. vMIADelta131-147 is a dominant-negative inhibitor of the antiapoptotic function of wild-type vMIA. Our experiments with vMIADelta131-147 suggest that vMIA forms homo-oligomers, which may engage in cooperative and/or multivalent interactions with Bax, leading to its functional neutralization.
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Affiliation(s)
- A-L Pauleau
- INSERM, U848, Pavillion de Recherche 1, Villejuif, France
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43
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Chen YN, Yamada H, Mao W, Matsuyama S, Aihara M, Araie M. Hypoxia-induced retinal ganglion cell death and the neuroprotective effects of beta-adrenergic antagonists. Brain Res 2007; 1148:28-37. [PMID: 17368577 DOI: 10.1016/j.brainres.2007.02.027] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Revised: 02/06/2007] [Accepted: 02/12/2007] [Indexed: 11/17/2022]
Abstract
Hypoxia-induced retinal ganglion cell (RGC) death has been implicated in glaucomatous optic neuropathy. However, the precise mechanism of death signaling and how neuroprotective agents affect it are still unclear. The aim of this study is to characterize the mechanisms of hypoxia-induced apoptosis of cultured purified RGCs and to study the neuroprotective effects of beta-adrenergic antagonists. Rat RGCs were purified utilizing a modified two-step immuno-panning procedure. First, the extent of apoptosis in RGCs under hypoxia was quantified. Next, the effects of glutamate-channel antagonists (MK801 or DNQX), Bax inhibiting peptide (BIP), and beta-adrenergic antagonists (betaxolol, nipradilol, timolol or carteolol) on hypoxia-induced RGC death were investigated by the cell viability assay. Third, the effects of beta-adrenergic antagonists on hypoxia-induced increase of intracellular calcium concentrations ([Ca(2+)](i)) and the additional effect of NO scavenger to nipradilol were evaluated. Apoptotic RGC percentages under hypoxia were significantly increased compared to the control. The viability of RGCs under hypoxia was not affected by MK801 or DNQX, whereas it was increased in a dose-dependent manner with exposure to BIP, and to betaxolol, nipradilol, timolol, but not to carteolol. These effective beta-adrenergic antagonists showed no significant change in hypoxia-induced [Ca(2+)](i) levels. The NO scavenger alleviated neuroprotective effect by nipradilol. In conclusion, purified RGC damage induced by hypoxia involves Bax-dependent apoptotic pathway, but mostly independent of glutamate receptor-mediated excitotoxicity. Betaxolol, timolol and nipradilol showed a protective effect against hypoxia-induced RGC death, which was thought to be irrelevant either to calcium channel or beta-adrenoceptor blocking effects.
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Affiliation(s)
- Yi-Ning Chen
- Department of Ophthalmology, University of Tokyo School of Medicine, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-8655, Japan
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Lachapelle G, Radicioni SM, Stankiewicz AR, Mosser DD. Acute acidification or amiloride treatment suppresses the ability of Hsp70 to inhibit heat-induced apoptosis. Apoptosis 2007; 12:1479-88. [PMID: 17431790 DOI: 10.1007/s10495-007-0068-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Inhibition of stress-induced apoptosis by the molecular chaperone protein Hsp70 is a contributing factor in tumorigenesis and suppression of this ability could increase the effectiveness of anti-tumor therapy. Tumor cells exist in an acidic environment and acute acidification can sensitize tumor cells to heat-induced cell death. However, the ability of Hsp70 to prevent apoptosis under these conditions has not been examined. The effect of acute acidification on heat-induced apoptosis was examined in a human T-cell line with tetracycline-regulated Hsp70 expression. Apoptosis was inhibited in cells exposed to hyperthermia in acidic media when examined 6 h after the heat stress, but resumed if cells were returned to physiological pH during this recovery period. Long-term proliferation assays showed that acute acidification sensitized cells to heat-induced apoptosis. Hsp70 expressing cells were also sensitized and this was correlated with a reduced ability to suppress the activation of JNK (c-jun N-terminal kinase), Bax and caspase-3. Further sensitization could be achieved with the NHE1 (Na(+)/H(+) exchanger) inhibitor HMA (5-(N, N-hexamethylene) amiloride), which potentiated JNK activation in heat-shocked cells. These results demonstrate that the ability of Hsp70 to suppress apoptosis is compromised when cells are exposed to hyperthermia in an acidic environment, which is correlated with an impaired ability to inhibit JNK activation.
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Affiliation(s)
- Guillaume Lachapelle
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
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Cao Z, Ye P, Long C, Chen K, Li X, Wang H. Effect of pioglitazone, a peroxisome proliferator-activated receptor gamma agonist, on ischemia-reperfusion injury in rats. Pharmacology 2007; 79:184-92. [PMID: 17356310 DOI: 10.1159/000100870] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Accepted: 11/24/2006] [Indexed: 11/19/2022]
Abstract
Two groups of rats were used to examine the effect of pioglitazone, a peroxisome proliferator-activated receptor gamma (PPARgamma) agonist, on rat hearts using an in vivo model of ischemia-reperfusion (I/R) to elucidate potential mechanisms. One group was the 30-min reperfusion group, which was further subdivided into sham (n=5), vehicle (n=6) and pioglitazone (3 mg x kg(-1), n=7) treatment groups with 30 min ischemia followed by 30 min reperfusion to detect data related to cardiac function and the area of myocardial infarction. The other group was the 120-min reperfusion group, subdivided into sham (n=5), vehicle (n=6), and pioglitazone 0.3 mg x kg(-1) (n=6), 1 mg x kg(-1) (n=7) and 3 mg x kg(-1) (n=6) treatment groups. Immunohistochemistry, in situ hybridization, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) and DNA agarose gel electrophoresis were performed to detect apoptosis and expressions of Bax, Bcl-2, caspase 3, MMP-2 and PPARgamma protein, and MMP-2 and PPARgamma mRNA. We found that, after acute treatment with pioglitazone, the ratio of necrosis to area at risk decreased by 28% (p<0.01) and that of necrosis to left ventricle was reduced by 32% (p<0.01), compared with the vehicle group. Heart rate and +dp/dt(max), representing the cardiac systolic function, as well as -dp/dt(max), the indicator of cardiac diastolic function, improved significantly at 1 and 30 min after reperfusion (p<0.05-0.01). Furthermore, myocardial apoptosis was significantly suppressed by acute treatment with pioglitazone as evidenced by the decreased number of TUNEL-positive myocytes and DNA ladder, enhanced Bcl-2 protein expression, reduced Bax and caspase 3 protein expression in a dose-dependent manner compared with vehicle-treated rats. In addition, acute treatment with pioglitazone dose-dependently increased PPARgamma expression and decreased MMP-2 expression at protein and mRNA levels. Our findings demonstrate that a PPARgamma agonist may protect the heart from I/R injury. The protective effect is likely to occur by reducing cardiomyocyte apoptosis and inhibiting MMP-2.
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Affiliation(s)
- Zeling Cao
- Department of Geriatric Cardiology, Chinese PLA General Hospital, Beijing, People's Republic of China
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Liang X, Liu Y, Zhang Q, Gao L, Han L, Ma C, Zhang L, Chen YH, Sun W. Hepatitis B virus sensitizes hepatocytes to TRAIL-induced apoptosis through Bax. J Immunol 2007; 178:503-10. [PMID: 17182590 DOI: 10.4049/jimmunol.178.1.503] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Hepatitis B virus (HBV) infection afflicts >300 million people worldwide and is a leading cause of hepatocyte death, cirrhosis, and hepatocellular carcinoma. While the morphological characteristics of dying hepatocytes are well documented, the molecular mechanisms leading to the death of hepatocytes during HBV infection are not well understood. TRAIL, the TNF-related apoptosis-inducing ligand, has recently been implicated in the death of hepatocytes under certain inflammatory but not normal conditions. To determine the potential roles of TRAIL in HBV-induced hepatitis, we examined the effects of HBV and its X protein (HBx) on TRAIL-induced hepatocyte apoptosis both in vivo and in vitro. We found that hepatitis and hepatic cell death in HBV transgenic mice were significantly inhibited by a soluble TRAIL receptor that blocks TRAIL function. We also found that HBV or HBx transfection of a hepatoma cell line significantly increased its sensitivity to TRAIL-induced apoptosis. The increase in TRAIL sensitivity were associated with a dramatic up-regulation of Bax protein expression. Knocking down Bax expression using Bax-specific small interference RNA blocked HBV-induced hepatitis and hepatocyte apoptosis. The degradation of caspases 3 and 9, but not that of Bid or caspase-8, was preferentially affected by Bax knockdown. These results establish that HBV sensitizes hepatocytes to TRAIL-induced apoptosis through Bax and that Bax-specific small interference RNA can be used to inhibit HBV-induced hepatic cell death.
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Affiliation(s)
- Xiaohong Liang
- Institute of Immunology, School of Medicine, Shandong University, Jinan, People's Republic of China
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Huang X, Choi JK, Park SR, Ha Y, Park H, Yoon SH, Park HC, Park JO, Choi BH. GM-CSF inhibits apoptosis of neural cells via regulating the expression of apoptosis-related proteins. Neurosci Res 2007; 58:50-7. [PMID: 17331604 DOI: 10.1016/j.neures.2007.01.015] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Revised: 01/08/2007] [Accepted: 01/24/2007] [Indexed: 11/19/2022]
Abstract
Recently, we reported that GM-CSF showed therapeutic effects on the spinal cord injury (SCI) in rat model possibly via its anti-apoptotic activity in the nervous system. This study investigated the molecular mechanism of its anti-apoptotic and neuroprotective effects in N2a neuroblastoma cells and in rat SCI model. GM-CSF inhibited staurosporine-induced cytotoxicity and apoptosis of N2a cells. Single administration of GM-CSF either intraperitoneally or locally using a gelfoam, clearly reduced the apoptotic events in the surrounding region of the injury site in rat SCI model. Immunohistochemical analysis showed that apoptosis of cells occurred mainly in the neurons, but not significantly in the astrocytes in the surrounding regions. In both N2a cells and in rat SCI model, GM-CSF actually reduced the expression of pro-apoptotic proteins (p53, p21(WAF1/CIP1) and Bax), while further induced that of an anti-apoptotic protein (Bcl-2). In the Basso-Beattie-Bresnahan (BBB) locomotor test, the single GM-CSF administration showed better behavioral recovery than the untreated control only at early times within 1 week after injury. Overall, GM-CSF was shown to exert its neuroprotective effect on the neural injury by regulating the expression of apoptosis related genes, providing the molecular basis on its anti-apoptotic activity. Longer administration of GM-CSF appeared to be necessary for the sustained functional recovery from SCI.
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Affiliation(s)
- Xian Huang
- Department of Neurosurgery, Inha University College of Medicine, Incheon, Republic of Korea
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Ju DS, Kim MJ, Bae JH, Song HS, Chung BS, Lee MK, Kang CD, Lee HS, Kim DW, Kim SH. Camptothecin acts synergistically with imatinib and overcomes imatinib resistance through Bcr-Abl independence in human K562 cells. Cancer Lett 2007; 252:75-85. [PMID: 17223257 DOI: 10.1016/j.canlet.2006.12.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Revised: 12/08/2006] [Accepted: 12/12/2006] [Indexed: 11/28/2022]
Abstract
In this study, we have tried to find new targets and effective drugs for imatinib-resistant chronic myelogenous leukemia (CML) cells displaying loss of Bcr-Abl kinase target dependence. The imatinib-resistant K562/R1, -R2 and -R3 cells showed profound declines of Bcr-Abl level and concurrently exhibited up-regulation of Bcl-2 and Ku70/80, and down-regulation of Bax, DNA-PKcs and BRCA1, suggesting that loss of Bcr-Abl after exposure to imatinib might be accompanied by other cell survival mechanism. K562/R3 cells were more sensitive to camptothecin (CPT)- and radiation-induced apoptosis than K562 cells, indicating hypersensitivity of imatinib-resistant cells to DNA damaging agents. Moreover, when K562 cells were treated with the combination of imatinib with CPT, the level of Bax and the cleavage of PARP-1 and DNA-PK were significantly increased in comparison with the effects of each drug. Therefore, our study suggests that CPT can be used to treat CML with loss of Bcr-Abl expression.
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Affiliation(s)
- Dong-Sik Ju
- Department of Biochemistry, Pusan National University School of Medicine, Busan 602-739, South Korea
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Jiang M, Pabla N, Murphy RF, Yang T, Yin XM, Degenhardt K, White E, Dong Z. Nutlin-3 protects kidney cells during cisplatin therapy by suppressing Bax/Bak activation. J Biol Chem 2006; 282:2636-45. [PMID: 17130128 PMCID: PMC2859169 DOI: 10.1074/jbc.m606928200] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Nutlins, the newly developed small molecule antagonists of MDM2, activate p53 and induce apoptosis in cancer cells, offering a novel strategy of chemotherapy. Recent studies have further suggested synergistic effects of nutlins with other chemotherapeutic drugs. However, it is unclear whether nutlins increase or decrease the side effects of these drugs in normal non-malignant cells or tissues. Cisplatin is a widely used chemotherapy drug, which has a major side effect of kidney injury. Here we show that Nutlin-3 protected kidney cells against cisplatin-induced apoptosis. The cytoprotective effects of Nutlin-3 were not related to its regulation of p53 or consequent gene expression during cisplatin treatment. Moreover, the protective effects were shown in MDM2-, MDM4-, or p53-deficient cells. On the other hand, Nutlin-3 suppressed mitochondrial events of apoptosis during cisplatin incubation, including Bax activation and cytochrome c release. Nutlin-3 attenuated cisplatin-induced oligomerization of Bax and Bak but not their interactions with Bcl-XL. In isolated mitochondria, Nutlin-3 inhibited cytochrome c release induced by Ca2+, Bim peptide, and recombinant tBid. Importantly, it blocked both Bax and Bak oligomerization under these conditions. Together, the results have uncovered a new pharmacological function of nutlins, i.e. suppression of Bax and Bak, two critical mediators of apoptosis.
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Affiliation(s)
- Man Jiang
- Department of Cellular Biology and Anatomy, Medical College of Georgia and Veterans Affairs Medical Center, Augusta, Georgia 30912
| | - Navjotsin Pabla
- Department of Cellular Biology and Anatomy, Medical College of Georgia and Veterans Affairs Medical Center, Augusta, Georgia 30912
| | | | - Tianxin Yang
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah 84148
| | - Xiao-Ming Yin
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
| | - Kurt Degenhardt
- Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, Rutgers University, Cancer Institute of New Jersey, Piscataway, New Jersey 08854
| | - Eileen White
- Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, Rutgers University, Cancer Institute of New Jersey, Piscataway, New Jersey 08854
| | - Zheng Dong
- Department of Cellular Biology and Anatomy, Medical College of Georgia and Veterans Affairs Medical Center, Augusta, Georgia 30912
- To whom correspondence should be addressed: Dept. of Cellular Biology and Anatomy, Medical College of Georgia, 1459 Laney Walker Blvd., Augusta, GA 30912. Tel.: 706-721-2825; Fax: 706-721-6120;
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Chitambar CR, Wereley JP, Matsuyama S. Gallium-induced cell death in lymphoma: role of transferrin receptor cycling, involvement of Bax and the mitochondria, and effects of proteasome inhibition. Mol Cancer Ther 2006; 5:2834-43. [PMID: 17121930 DOI: 10.1158/1535-7163.mct-06-0285] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Gallium nitrate is a metallodrug with clinical efficacy in non-Hodgkin's lymphoma. Its mechanisms of antineoplastic action are not fully understood. In the present study, we investigated the roles of transferrin receptor (TfR) targeting and apoptotic pathways in gallium-induced cell death. Although DoHH2 lymphoma cells displayed a 3-fold lower number of TfRs than CCRF-CEM lymphoma cells, they were 3- to 4-fold more sensitive to gallium nitrate. Despite a lower TfR expression, DoHH2 cells had greater TfR cycling and iron and gallium uptake than CCRF-CEM cells. In other lymphoma cell lines, TfR levels per se did not correlate with gallium sensitivity. Cells incubated with gallium nitrate showed morphologic changes of apoptosis, which were decreased by the caspase inhibitor Z-VAD-FMK and by a Bax-inhibitory peptide. Cells exposed to gallium nitrate released cytochrome c from mitochondria and displayed a dose-dependent increase in caspase-3 activity. An increase in active Bax levels without accompanying changes in Bcl-2 or Bcl-X(L) was seen in cells incubated with gallium nitrate. The endogenous expression of antiapoptotic Bcl-2 was greater in DoHH2 cells than in CCRF-CEM cells, suggesting that endogenous Bcl-2 levels do not correlate with cell sensitivity to gallium nitrate. Gallium-induced apoptosis was enhanced by the proteasome inhibitor bortezomib. Our results suggest that TfR function rather than TfR number is important in gallium targeting to cells and that apoptosis is triggered by gallium through the mitochondrial pathway by activating proapoptotic Bax. Our studies also suggest that the antineoplastic activity of combination gallium nitrate and bortezomib warrants further investigation.
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Affiliation(s)
- Christopher R Chitambar
- Division of Neoplastic Diseases, Department of Medicine, Medical College of Wisconsin, 9200 West Wisconsin Avenue, Milwaukee, WI 53226.
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