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DeMambro VE, Tian L, Karthik V, Rosen CJ, Guntur AR. Effects of PTH on osteoblast bioenergetics in response to glucose. Bone Rep 2023; 19:101705. [PMID: 37576927 PMCID: PMC10412867 DOI: 10.1016/j.bonr.2023.101705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 05/29/2023] [Accepted: 07/13/2023] [Indexed: 08/15/2023] Open
Abstract
Parathyroid hormone acts through its receptor, PTHR1, expressed on osteoblasts, to control bone remodeling. Metabolic flexibility for energy generation has been demonstrated in several cell types dependent on substrate availability. Recent studies have identified a critical role for PTH in regulating glucose, fatty acid and amino acid metabolism thus stimulating both glycolysis and oxidative phosphorylation. Therefore, we postulated that PTH stimulates increased energetic output by osteoblasts either by increasing glycolysis or oxidative phosphorylation depending on substrate availability. To test this hypothesis, undifferentiated and differentiated MC3T3E1C4 calvarial pre-osteoblasts were treated with PTH to study osteoblast bioenergetics in the presence of exogenous glucose. Significant increases in glycolysis with acute ∼1 h PTH treatment with minimal effects on oxidative phosphorylation in undifferentiated MC3T3E1C4 in the presence of exogenous glucose were observed. In differentiated cells, the increased glycolysis observed with acute PTH was completely blocked by pretreatment with a Glut1 inhibitor (BAY-876) resulting in a compensatory increase in oxidative phosphorylation. We then tested the effect of PTH on the function of complexes I and II of the mitochondrial electron transport chain in the absence of glycolysis. Utilizing a novel cell plasma membrane permeability mitochondrial (PMP) assay, in combination with complex I and II specific substrates, slight but significant increases in basal and maximal oxygen consumption rates with 24 h PTH treatment in undifferentiated MC3T3E1C4 cells were noted. Taken together, our data demonstrate for the first time that PTH stimulates both increases in glycolysis and the function of the electron transport chain, particularly complexes I and II, during high energy demands in osteoblasts.
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Affiliation(s)
- Victoria E. DeMambro
- Center for Molecular Medicine, MaineHealth Institute for Research, Scarborough, ME, USA
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, USA
| | - Li Tian
- Center for Molecular Medicine, MaineHealth Institute for Research, Scarborough, ME, USA
| | - Vivin Karthik
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, USA
| | - Clifford J. Rosen
- Center for Molecular Medicine, MaineHealth Institute for Research, Scarborough, ME, USA
- Tufts University School of Medicine, Tufts University, Boston, MA, USA
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, USA
| | - Anyonya R. Guntur
- Center for Molecular Medicine, MaineHealth Institute for Research, Scarborough, ME, USA
- Tufts University School of Medicine, Tufts University, Boston, MA, USA
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, USA
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Chlebek C, Rosen CJ. The Role of Bone Cell Energetics in Altering Bone Quality and Strength in Health and Disease. Curr Osteoporos Rep 2023; 21:1-10. [PMID: 36435911 DOI: 10.1007/s11914-022-00763-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/26/2022] [Indexed: 11/28/2022]
Abstract
PURPOSE OF REVIEW Bone quality and strength are diminished with age and disease but can be improved by clinical intervention. Energetic pathways are essential for cellular function and drive osteogenic signaling within bone cells. Altered bone quality is associated with changes in the energetic activity of bone cells following diet-based or therapeutic interventions. Energetic pathways may directly or indirectly contribute to changes in bone quality. The goal of this review is to highlight tissue-level and bioenergetic changes in bone health and disease. RECENT FINDINGS Bone cell energetics are an expanding field of research. Early literature primarily focused on defining energetic activation throughout the lifespan of bone cells. Recent studies have begun to connect bone energetic activity to health and disease. In this review, we highlight bone cell energetic demands, the effect of substrate availability on bone quality, altered bioenergetics associated with disease treatment and development, and additional biological factors influencing bone cell energetics. Bone cells use several energetic pathways during differentiation and maturity. The orchestration of bioenergetic pathways is critical for healthy cell function. Systemic changes in substrate availability alter bone quality, potentially due to the direct effects of altered bone cell bioenergetic activity. Bone cell bioenergetics may also contribute directly to the development and treatment of skeletal diseases. Understanding the role of energetic pathways in the cellular response to disease will improve patient treatment.
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Affiliation(s)
- Carolyn Chlebek
- Maine Medical Center Research Institute, 81 Research Drive, Scarborough, ME, USA
| | - Clifford J Rosen
- Maine Medical Center Research Institute, 81 Research Drive, Scarborough, ME, USA.
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Parathyroid hormone (PTH) regulation of metabolic homeostasis: An old dog teaches us new tricks. Mol Metab 2022; 60:101480. [PMID: 35338013 PMCID: PMC8980887 DOI: 10.1016/j.molmet.2022.101480] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 02/11/2022] [Accepted: 03/16/2022] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Late in the nineteenth century, it was theorized that a circulating product produced by the parathyroid glands could negatively impact skeletal homeostasis. A century later, intermittent administration of that protein, namely parathyroid hormone (PTH), was approved by the FDA and EMA as the first anabolic agent to treat osteoporosis. Yet, several unanswered but important questions remain about the skeletal actions of PTH. SCOPE OF REVIEW Current research efforts have focused on improving the efficacy of PTH treatment by designing structural analogs and identifying other targets (e.g., the PTH or the calcium sensing receptor). A unique but only recently described aspect of PTH action is its regulation of cellular bioenergetics and metabolism, namely in bone and adipose tissue but also in other tissues. The current review aims to provide a brief background on PTH's previously described actions on bone and highlights how PTH regulates osteoblast bioenergetics, contributing to greater bone formation. It will also shed light on how PTH could alter metabolic homeostasis through its actions in other cells and tissues, thereby impacting the skeleton in a cell non-autonomous manner. MAJOR CONCLUSIONS PTH administration enhances bone formation by targeting the osteoblast through transcriptional changes in several pathways; the most prominent is via adenyl cyclase and PKA. PTH and its related protein, PTHrP, also induce glycolysis and fatty acid oxidation in bone cells and drive lipolysis and thermogenic programming in adipocytes; the latter may indirectly but positively influence skeletal metabolism. While much work remains, alterations in cellular metabolism may also provide a novel mechanism related to PTH's temporal actions. Thus, the bioenergetic impact of PTH can be considered another of the myriad anabolic effects of PTH on the skeleton. Just as importantly from a translational perspective, the non-skeletal metabolic effects may lead to a better understanding of whole-body homeostasis along with new and improved therapies to treat musculoskeletal conditions.
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Chen H, Shi P, Xu Z, Fan F, Wang Z, Du M. Oral Administration of Oyster Peptide Prevents Bone Loss in Ovariectomized Mice. EFOOD 2020. [DOI: 10.2991/efood.k.200812.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
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Shrirao AB, Kung FH, Omelchenko A, Schloss RS, Boustany NN, Zahn JD, Yarmush ML, Firestein BL. Microfluidic platforms for the study of neuronal injury in vitro. Biotechnol Bioeng 2018; 115:815-830. [PMID: 29251352 DOI: 10.1002/bit.26519] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 12/11/2017] [Accepted: 12/15/2017] [Indexed: 12/27/2022]
Abstract
Traumatic brain injury (TBI) affects 5.3 million people in the United States, and there are 12,500 new cases of spinal cord injury (SCI) every year. There is yet a significant need for in vitro models of TBI and SCI in order to understand the biological mechanisms underlying central nervous system (CNS) injury and to identify and test therapeutics to aid in recovery from neuronal injuries. While TBI or SCI studies have been aided with traditional in vivo and in vitro models, the innate limitations in specificity of injury, isolation of neuronal regions, and reproducibility of these models can decrease their usefulness in examining the neurobiology of injury. Microfluidic devices provide several advantages over traditional methods by allowing researchers to (1) examine the effect of injury on specific neural components, (2) fluidically isolate neuronal regions to examine specific effects on subcellular components, and (3) reproducibly create a variety of injuries to model TBI and SCI. These microfluidic devices are adaptable for modeling a wide range of injuries, and in this review, we will examine different methodologies and models recently utilized to examine neuronal injury. Specifically, we will examine vacuum-assisted axotomy, physical injury, chemical injury, and laser-based axotomy. Finally, we will discuss the benefits and downsides to each type of injury model and discuss how researchers can use these parameters to pick a particular microfluidic device to model CNS injury.
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Affiliation(s)
- Anil B Shrirao
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey
| | - Frank H Kung
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey
| | - Anton Omelchenko
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey
| | - Rene S Schloss
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey
| | - Nada N Boustany
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey
| | - Jeffrey D Zahn
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey
| | - Martin L Yarmush
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey
| | - Bonnie L Firestein
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey
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Navein AE, Cooke EJ, Davies JR, Smith TG, Wells LHM, Ohazama A, Healy C, Sharpe PT, Evans SL, Evans BAJ, Votruba M, Wells T. Disrupted mitochondrial function in the Opa3L122P mouse model for Costeff Syndrome impairs skeletal integrity. Hum Mol Genet 2016; 25:2404-2416. [PMID: 27106103 PMCID: PMC5181626 DOI: 10.1093/hmg/ddw107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 03/29/2016] [Accepted: 03/30/2016] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial dysfunction connects metabolic disturbance with numerous pathologies, but the significance of mitochondrial activity in bone remains unclear. We have, therefore, characterized the skeletal phenotype in the Opa3L122P mouse model for Costeff syndrome, in which a missense mutation of the mitochondrial membrane protein, Opa3, impairs mitochondrial activity resulting in visual and metabolic dysfunction. Although widely expressed in the developing normal mouse head, Opa3 expression was restricted after E14.5 to the retina, brain, teeth and mandibular bone. Opa3 was also expressed in adult tibiae, including at the trabecular surfaces and in cortical osteocytes, epiphyseal chondrocytes, marrow adipocytes and mesenchymal stem cell rosettes. Opa3L122P mice displayed craniofacial abnormalities, including undergrowth of the lower mandible, accompanied in some individuals by cranial asymmetry and incisor malocclusion. Opa3L122P mice showed an 8-fold elevation in tibial marrow adiposity, due largely to increased adipogenesis. In addition, femoral length and cortical diameter and wall thickness were reduced, the weakening of the calcified tissue and the geometric component of strength reducing overall cortical strength in Opa3L122P mice by 65%. In lumbar vertebrae reduced vertebral body area and wall thickness were accompanied by a proportionate reduction in marrow adiposity. Although the total biomechanical strength of lumbar vertebrae was reduced by 35%, the strength of the calcified tissue (σmax) was proportionate to a 38% increase in trabecular number. Thus, mitochondrial function is important for the development and maintenance of skeletal integrity, impaired bone growth and strength, particularly in limb bones, representing a significant new feature of the Costeff syndrome phenotype.
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Affiliation(s)
- Alice E Navein
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - Esther J Cooke
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - Jennifer R Davies
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4LU, UK
| | - Terence G Smith
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4LU, UK
| | - Lois H M Wells
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK.,Caerleon Comprehensive School, Caerleon, Newport NP18 1NF, UK
| | - Atsushi Ohazama
- Department of Craniofacial Development and Stem Cell Biology, King's College London, Guy's Hospital, London SE1 9RT, UK
| | - Christopher Healy
- Department of Craniofacial Development and Stem Cell Biology, King's College London, Guy's Hospital, London SE1 9RT, UK
| | - Paul T Sharpe
- Department of Craniofacial Development and Stem Cell Biology, King's College London, Guy's Hospital, London SE1 9RT, UK
| | - Sam L Evans
- School of Engineering, Cardiff University, The Parade, Cardiff CF24 3AA, UK
| | - Bronwen A J Evans
- Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
| | - Marcela Votruba
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4LU, UK.,Cardiff Eye Unit, University Hospital of Wales, Heath Park, Cardiff CF14 4XW, UK
| | - Timothy Wells
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
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Wan J, Deng L, Zhang C, Yuan Q, Liu J, Dun Y, Zhou Z, Zhao H, Liu C, Yuan D, Wang T. Chikusetsu saponin V attenuates H2O2-induced oxidative stress in human neuroblastoma SH-SY5Y cells through Sirt1/PGC-1α/Mn-SOD signaling pathways. Can J Physiol Pharmacol 2016; 94:919-28. [PMID: 27332950 DOI: 10.1139/cjpp-2015-0262] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Oxidative stress plays a vital role in the pathogenesis of neurodegenerative diseases. Chikusetsu saponin V (CsV), the most abundant member of saponins from Panax japonicus (SPJ), has attracted increasing attention for its potential to treat neurodegenerative diseases. However, the mechanisms are unclear. Our study intended to investigate the antioxidative effects of CsV in human neuroblastoma SH-SY5Y cells. Our data showed that CsV attenuated H2O2-induced cytotoxicity, inhibited ROS accumulation, increased the activities of superoxide dismutase (SOD) and GSH, and increased mitochondrial membrane potential dose-dependently. Further exploration of the mechanisms showed that CsV exhibited these effects through increasing the activation of oxidative-stress-associated factors including Sirt1, PGC-1α, and Mn-SOD. Moreover, CsV inhibited H2O2-induced down-regulation of Bcl-2 and up-regulation of Bax in a dose-dependent manner and, thus, increased the ratio of Bcl-2/Bax. In conclusion, our study demonstrated that CsV exhibited neuroprotective effects possibly through Sirt1/PGC-1α/Mn-SOD signaling pathways.
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Affiliation(s)
- Jingzhi Wan
- a College of Medical Science, Three Gorges University, Yichang, Hubei 443002, China
| | - Lili Deng
- a College of Medical Science, Three Gorges University, Yichang, Hubei 443002, China
| | - Changcheng Zhang
- a College of Medical Science, Three Gorges University, Yichang, Hubei 443002, China
| | - Qin Yuan
- a College of Medical Science, Three Gorges University, Yichang, Hubei 443002, China
| | - Jing Liu
- a College of Medical Science, Three Gorges University, Yichang, Hubei 443002, China
| | - Yaoyan Dun
- a College of Medical Science, Three Gorges University, Yichang, Hubei 443002, China
| | - Zhiyong Zhou
- a College of Medical Science, Three Gorges University, Yichang, Hubei 443002, China
| | - Haixia Zhao
- a College of Medical Science, Three Gorges University, Yichang, Hubei 443002, China
| | - Chaoqi Liu
- b Three Gorges University Institute of Molecular Biology, Yichang, Hubei 443002, China
| | - Ding Yuan
- c Renhe Hospital, The second College of Clinical Medical Science, Three Gorges University, Yichang, Hubei 443001, China
| | - Ting Wang
- a College of Medical Science, Three Gorges University, Yichang, Hubei 443002, China
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Yu B, Yang Y, Liu H, Gong M, Millard RW, Wang YG, Ashraf M, Xu M. Clusterin/Akt Up-Regulation Is Critical for GATA-4 Mediated Cytoprotection of Mesenchymal Stem Cells against Ischemia Injury. PLoS One 2016; 11:e0151542. [PMID: 26962868 PMCID: PMC4786134 DOI: 10.1371/journal.pone.0151542] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 02/29/2016] [Indexed: 01/12/2023] Open
Abstract
Background Clusterin (Clu) is a stress-responding protein with multiple biological functions. Our preliminary microarray studies show that clusterin was prominently upregulated in mesenchymal stem cells (MSCs) overexpressing GATA-4 (MSCGATA-4). We hypothesized that the upregulation of clusterin is involved in overexpression of GATA-4 mediated cytoprotection. Methods MSCs harvested from bone marrow of rats were transduced with GATA-4. The expression of clusterin in MSCs was further confirmed by real-time PCR and western blotting. Simulation of ischemia was achieved by exposure of MSCs to a hypoxic environment. Lactate dehydrogenase (LDH) released from MSCs was served as a biomarker of cell injury and MTs uptake was used to estimate cell viability. Mitochondrial function was evaluated by measuring mitochondrial membrane potential (ΔΨm) and caspase 3/7 activity. Results (1) Clusterin expression was up-regulated in MSCGATA-4 compared to control MSCs transfected with empty-vector (MSCNull). MSCGATA-4 were tolerant to 72 h hypoxia exposure as shown by reduced LDH release and higher MTs uptake. This protection was abrogated by transfecting Clu-siRNA into MSCGATA-4. (2) Exogenous clusterin significantly decreased LDH release and increased MSC survival in hypoxic environment. Moreover, ΔΨm was maintained and caspase 3/7 activity was reduced by clusterin in a concentration-dependent manner. (3) p-Akt expression in MSCs was upregulated following pre-treatment with clusterin, with no change in total Akt. Moreover, cytoprotection mediated by clusterin was partially abrogated by Akt inhibitor LY294002. Conclusions Clusterin/Akt signaling pathway is involved in GATA-4 mediated cytoprotection against hypoxia stress. It is suggested that clusterin may be therapeutically exploited in MSC based therapy for cardiovascular diseases.
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Affiliation(s)
- Bin Yu
- Department of Pathology and Laboratory Medicine, University of Cincinnati Medical Center, Cincinnati, Ohio, United States of America
| | - Yueting Yang
- Department of Pathology and Laboratory Medicine, University of Cincinnati Medical Center, Cincinnati, Ohio, United States of America
| | - Huan Liu
- Department of Pathology and Laboratory Medicine, University of Cincinnati Medical Center, Cincinnati, Ohio, United States of America
| | - Min Gong
- Department of Pathology and Laboratory Medicine, University of Cincinnati Medical Center, Cincinnati, Ohio, United States of America
| | - Ronald W. Millard
- Department of Pharmacology & Cell Biophysics, University of Cincinnati Medical Center, Cincinnati, Ohio, United States of America
| | - Yi-Gang Wang
- Department of Pathology and Laboratory Medicine, University of Cincinnati Medical Center, Cincinnati, Ohio, United States of America
| | - Muhammad Ashraf
- Department of Pathology and Laboratory Medicine, University of Cincinnati Medical Center, Cincinnati, Ohio, United States of America
| | - Meifeng Xu
- Department of Pathology and Laboratory Medicine, University of Cincinnati Medical Center, Cincinnati, Ohio, United States of America
- * E-mail:
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Dollé JP, Morrison B, Schloss RS, Yarmush ML. Brain-on-a-chip microsystem for investigating traumatic brain injury: Axon diameter and mitochondrial membrane changes play a significant role in axonal response to strain injuries. TECHNOLOGY 2014; 2:106. [PMID: 25101309 PMCID: PMC4120884 DOI: 10.1142/s2339547814500095] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Diffuse axonal injury (DAI) is a devastating consequence of traumatic brain injury, resulting in significant axon and neuronal degeneration. Currently, therapeutic options are limited. Using our brain-on-a-chip device, we evaluated axonal responses to DAI. We observed that axonal diameter plays a significant role in response to strain injury, which correlated to delayed elasticity and inversely correlated to axonal beading and axonal degeneration. When changes in mitochondrial membrane potential (MMP) were monitored an applied strain injury threshold was noted, below which delayed hyperpolarization was observed and above which immediate depolarization occurred. When the NHE-1 inhibitor EIPA was administered before injury, inhibition in both hyperpolarization and depolarization occurred along with axonal degeneration. Therefore, axonal diameter plays a significant role in strain injury and our brain-on-a-chip technology can be used both to understand the biochemical consequences of DAI and screen for potential therapeutic agents.
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10
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Yu B, Gong M, He Z, Wang YG, Millard RW, Ashraf M, Xu M. Enhanced mesenchymal stem cell survival induced by GATA-4 overexpression is partially mediated by regulation of the miR-15 family. Int J Biochem Cell Biol 2013; 45:2724-35. [PMID: 24070634 DOI: 10.1016/j.biocel.2013.09.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 08/12/2013] [Accepted: 09/16/2013] [Indexed: 01/12/2023]
Abstract
UNLABELLED We reported previously that pre-programming mesenchymal stem cells with the GATA-4 gene increases significantly cell survival in an ischemic environment. In this study, we tested whether regulation of microRNAs and their target proteins was associated with the cytoprotective effects of GATA-4. METHODS AND RESULTS Mesenchymal stem cells were harvested from adult rat bone marrow and transduced with GATA-4 (MSC(GATA-4)) using the murine stem cell virus retroviral expression system. Cells transfected with empty vector (MSC(Null)) were used as controls. Quantitative real-time PCR data showed that the expression levels of miR-15 family members (miR-15b, miR-16, and miR-195) were significantly down-regulated in MSC(GATA-4). The protein expression of Bcl-w (Bcl-2-like-2), an anti-apoptotic Bcl-2 family protein, was increased in MSC(GATA-4). Hypoxic culture (low glucose and low oxygen) induced the release of lactate dehydrogenase from mesenchymal stem cells and reduced cell survival. Compared to MSC(Null), MSC(GATA-4) showed less lactate dehydrogenase release and greater cell survival following 72 h hypoxia exposure. The mitochondrial membrane potential, detected with the dye JC-1, was well maintained, and mitochondrial membrane permeability, expressed as caspase 3 and 7 activities in response to the ischemic environment was lower in MSC(GATA-4). Moreover, transfection with miR-195 significantly down-regulated Bcl-w expression in mesenchymal stem cells through a binding site in the 3'-UTR of the Bcl-w mRNA and reduced mesenchymal stem cell resistance to ischemic injury. CONCLUSIONS The overexpression of GATA-4 in mesenchymal stem cells down-regulates miR-15 family members, causing increased resistance to ischemia through the up-regulation of anti-apoptotic proteins in the Bcl-2 family.
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Affiliation(s)
- Bin Yu
- Department of Pathology and Laboratory Medicine, University of Cincinnati Medical Center, Cincinnati, OH, USA
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11
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Huang T, Lin J, Cao J, Zhang P, Bai Y, Chen G, Chen K. An exopolysaccharide from Trichoderma pseudokoningii and its apoptotic activity on human leukemia K562 cells. Carbohydr Polym 2012; 89:701-8. [PMID: 24750776 DOI: 10.1016/j.carbpol.2012.03.079] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Revised: 03/22/2012] [Accepted: 03/24/2012] [Indexed: 11/30/2022]
Abstract
In this study, a novel exopolysaccharide (EPS) was isolated from the fermentation broth of Trichoderma pseudokoningii and its anticancer activities on human leukemia K562 cells were studied. EPS could significantly inhibited K562 cells proliferation in a time- and concentration-dependent manner. Meanwhile, characteristic of apoptosis, including apoptotic morphological features and the apoptosis rate were obtained. Sequentially, the dissipation of mitochondrial membrane potential, increase production of Reactive oxygen species (ROS), enhancement of the concentration of intracellular, up-regulation of Bax and p53 mRNA, down-regulation of Bcl-2 mRNA were also detected. The results indicate that the EPS could induce of K562 cells apoptosis, primarily in involved the mitochondrial pathways. The present studies suggest that EPS could be a new potential adjuvant chemotherapeutic and chemo preventive agent against human leukemia.
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Affiliation(s)
- Taotao Huang
- School of Life Sciences, Shandong University, Jinan 250100, PR China
| | - Jun Lin
- Department of Pharmacy, Wannan Medical college, Wuhu 241000, PR China
| | - Jianfeng Cao
- School of Life Sciences, Shandong University, Jinan 250100, PR China
| | - Pengying Zhang
- School of Life Sciences, Shandong University, Jinan 250100, PR China; National Glycoengineering Research Center, School of Life Science, Shandong University, Jinan 250100, PR China
| | - Yungui Bai
- School of Life Sciences, Shandong University, Jinan 250100, PR China
| | - Guochuang Chen
- School of Life Sciences, Shandong University, Jinan 250100, PR China
| | - Kaoshan Chen
- School of Life Sciences, Shandong University, Jinan 250100, PR China; Department of Pharmacy, Wannan Medical college, Wuhu 241000, PR China; National Glycoengineering Research Center, School of Life Science, Shandong University, Jinan 250100, PR China
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12
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Liao P, Liu W, Li H, Gao H, Wang H, Li N, Xu N, Li J, Wan J, Liu L, Sun Y. Morphological changes of ricin toxin-induced apoptosis in human cervical cancer cells. Toxicol Ind Health 2011; 28:439-48. [DOI: 10.1177/0748233711414608] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The morphological changes of ricin-induced apoptosis in a human cervical cancer cell line were studied. To shed light on the mechanism of action of ricin toxin (RT) at the cellular level, we examined cell growth, apoptosis, changes of mitochondrial membrane potential (MMP) and cytochrome C translocation in HeLa cells by exposing these cells to RT for indicated times. The effect of RT on cell proliferation was measured by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), inner salt; MTS assay and apoptosis were measured using flow cytometry, fluorescence microscopy and electron microscopy. Changes in MMP were monitored using flow cytometry. Western blot analysis was used to evaluate the release of mitochondrial cytochrome C. RT noticeably inhibited the proliferation of HeLa cells, and the half maximal inhibitory concentration dose was about 100 ng/ml. HeLa cells treated with RT showed typical characteristics of apoptosis rather than necrosis, including phosphatidylserine exposed from the inner to the outer leaflet of the plasma membrane, abnormal cell morphology, chromatin condensation and nuclear fragmentation. In contrast, during the process of cellular apoptosis, the messenger RNA (mRNA) and protein expression of cytochrome C in treated and untreated Hela cells were not significantly changed (data not shown). However, when cells were treated with RT, the massive translocation of cytochrome C to the nucleus was evident. Our results indicate that RT-induced HeLa cell apoptosis, especially for cytochrome C translocation, may play an important role in apoptosis induced by RT.
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Affiliation(s)
- Peng Liao
- College of Animal Science and Veterinary Medicine, Jilin University, Jilin, China
- Institute of Military Veterinary Medical Science, Academy of Military Medical Science, Jilin, China
- Key Laboratory of Jilin Province for Zoonoses Prevention and Control, Jilin, China
| | - Wensen Liu
- Institute of Military Veterinary Medical Science, Academy of Military Medical Science, Jilin, China
- Key Laboratory of Jilin Province for Zoonoses Prevention and Control, Jilin, China
| | - Hongyang Li
- College of Animal Science and Veterinary Medicine, Jilin University, Jilin, China
| | - Hongwei Gao
- Institute of Military Veterinary Medical Science, Academy of Military Medical Science, Jilin, China
- Key Laboratory of Jilin Province for Zoonoses Prevention and Control, Jilin, China
| | - Haiying Wang
- College of Animal Science and Veterinary Medicine, Jilin University, Jilin, China
- Institute of Military Veterinary Medical Science, Academy of Military Medical Science, Jilin, China
- Key Laboratory of Jilin Province for Zoonoses Prevention and Control, Jilin, China
| | - Nan Li
- Institute of Military Veterinary Medical Science, Academy of Military Medical Science, Jilin, China
- Key Laboratory of Jilin Province for Zoonoses Prevention and Control, Jilin, China
| | - Na Xu
- Department of the Dean’s Office, Medical College of Jilin, Jilin, China
| | - Jiping Li
- Institute of Military Veterinary Medical Science, Academy of Military Medical Science, Jilin, China
- Key Laboratory of Jilin Province for Zoonoses Prevention and Control, Jilin, China
| | - Jiayu Wan
- Institute of Military Veterinary Medical Science, Academy of Military Medical Science, Jilin, China
- Key Laboratory of Jilin Province for Zoonoses Prevention and Control, Jilin, China
| | - Linna Liu
- Institute of Military Veterinary Medical Science, Academy of Military Medical Science, Jilin, China
- Key Laboratory of Jilin Province for Zoonoses Prevention and Control, Jilin, China
| | - Yucheng Sun
- Institute of Military Veterinary Medical Science, Academy of Military Medical Science, Jilin, China
- Key Laboratory of Jilin Province for Zoonoses Prevention and Control, Jilin, China
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13
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Xie J, Duan L, Qian X, Huang X, Ding J, Hu G. KATP channel openers protect mesencephalic neurons against MPP+-induced cytotoxicity via inhibition of ROS production. J Neurosci Res 2010; 88:428-37. [DOI: 10.1002/jnr.22213] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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14
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Troiano L, Ferraresi R, Lugli E, Nemes E, Roat E, Nasi M, Pinti M, Cossarizza A. Multiparametric analysis of cells with different mitochondrial membrane potential during apoptosis by polychromatic flow cytometry. Nat Protoc 2008; 2:2719-27. [PMID: 18007607 DOI: 10.1038/nprot.2007.405] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The analysis of changes in mitochondrial membrane potential (MMP) that can occur during apoptosis provides precious information on the mechanisms and pathways of cell death. For many years, the metachromatic fluorochrome JC-1 (5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide) was used for this purpose. Thanks to new dyes and to the technical improvements recently adopted in several flow cytometers, it is now possible to investigate, along with MMP, a variety of other parameters. Using three sources of excitation and polychromatic flow cytometry, we have developed a protocol that can be applied to cells undergoing apoptosis. In the model of U937 cells incubated with the chemopreventive agent quercetin (3,3',4',5,7-pentahydroxyflavone), we describe the detection at the single cell level of changes in MMP (by JC-1), early apoptosis (exposition of phosphatidylserine on the plasma membrane detected by annexin-V), late apoptosis and secondary necrosis (decreased DNA content by Hoechst 33342 and permeability of the plasma membrane to propidium iodide). The procedure can be completed in less than 2 h.
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Affiliation(s)
- Leonarda Troiano
- Department of Biomedical Sciences, University of Modena and Reggio Emilia, via Campi 287, 41100 Modena, Italy
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15
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Soares SS, Gutiérrez-Merino C, Aureliano M. Mitochondria as a target for decavanadate toxicity in Sparus aurata heart. AQUATIC TOXICOLOGY 2007; 83:1-9. [PMID: 17420061 DOI: 10.1016/j.aquatox.2007.03.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Revised: 03/07/2007] [Accepted: 03/08/2007] [Indexed: 02/07/2023]
Abstract
In a previous in vivo study we have reported that vanadium distribution, antioxidant enzymes activity and lipid peroxidation in Sparus aurata heart are strongly dependent on the oligomeric vanadate species being administered. Moreover, it was suggested that vanadium is accumulated in mitochondria, in particular when V10 was intravenously injected. In this work we have done a comparative study of the effects of V10 and monomeric vanadate (V1) on cardiac mitochondria from S. aurata. V10 inhibits mitochondrial oxygen consumption with an IC(50) of 400 nM, while the IC(50) for V1 is 23 microM. V10 also induced mitochondrial depolarization at very low concentrations, with an IC(50) of 196 nM, and 55 microM of V1 was required to induce the same effect. Additionally, up to 5 microM V10 did inhibit neither F(0)F(1)-ATPase activity nor NADH levels and it did not affect respiratory complexes I and II, but it induced changes in the redox steady-state of complex III. It is concluded that V10 inhibits mitochondrial oxygen consumption and induces membrane depolarization more strongly than V1, pointing out that mitochondria is a toxicological target for V10 and the importance to take into account the contribution of V10 to the vanadate toxic effects.
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Affiliation(s)
- Sandra S Soares
- Faculty of Sciences and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
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16
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Soares SS, Gutiérrez-Merino C, Aureliano M. Decavanadate induces mitochondrial membrane depolarization and inhibits oxygen consumption. J Inorg Biochem 2007; 101:789-96. [PMID: 17349695 DOI: 10.1016/j.jinorgbio.2007.01.012] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Revised: 01/19/2007] [Accepted: 01/24/2007] [Indexed: 02/07/2023]
Abstract
Decavanadate induced rat liver mitochondrial depolarization at very low concentrations, half-depolarization with 39 nM decavanadate, while it was needed a 130-fold higher concentration of monomeric vanadate (5 microM) to induce the same effect. Decavanadate also inhibits mitochondrial repolarization induced by reduced glutathione in vitro, with an inhibition constant of 1 microM, whereas no effect was observed up to 100 microM of monomeric vanadate. The oxygen consumption by mitochondria is also inhibited by lower decavanadate than monomeric vanadate concentrations, i.e. 50% inhibition is attained with 99 M decavanadate and 10 microM monomeric vanadate. Thus, decavanadate is stronger as mitochondrial depolarization agent than as inhibitor of mitochondrial oxygen consumption. Up to 5 microM, decavanadate does not alter mitochondrial NADH levels nor inhibit neither F(O)F(1)-ATPase nor cytochrome c oxidase activity, but it induces changes in the redox steady-state of mitochondrial b-type cytochromes (complex III). NMR spectra showed that decameric vanadate is the predominant vanadate species in decavanadate solutions. It is concluded that decavanadate is much more potent mitochondrial depolarization agent and a more potent inhibitor of mitochondrial oxygen consumption than monomeric vanadate, pointing out the importance to take into account the contribution of higher oligomeric species of vanadium for the biological effects of vanadate solutions.
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Affiliation(s)
- S S Soares
- Centro de Ciências do Mar, Faculdade de Ciências e Tecnologia, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
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17
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Yao G, Ling L, Luan J, Ye D, Zhu P. Nonylphenol induces apoptosis of Jurkat cells by a caspase-8 dependent mechanism. Int Immunopharmacol 2007; 7:444-53. [PMID: 17321467 DOI: 10.1016/j.intimp.2006.11.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2006] [Revised: 11/28/2006] [Accepted: 11/29/2006] [Indexed: 11/28/2022]
Abstract
Nonylphenol is the final biodegradation product of nonylphenol polyethoxylates, which are widely used surfactants in domestic and industrial products. Although nonylphenol is well known as an endocrine disrupting chemical, its effects on cell death and the mechanisms responsible for these apoptotic effects remain unclear. In the present study, Jurkat cells were treated with 0.1, 1 and 10 microM nonylphenol for 12 and 24 h, respectively. Cell viability was assessed with a Cell Counting Kit. The effects of nonylphenol on apoptosis of Jurkat cells were determined by DNA fragmentation (DNA ladder), Hoechst33258, PI and Annexin V FITC/PI double staining. Changes in mitochondrial membrane potential were detected with JC-1 fluorescence. In addition, enzyme activity of caspase-8 was evaluated by flow cytometry. The results demonstrated that nonylphenol inhibited the proliferation and induced loss of mitochondrial membrane potential, caspase-8 activation, internucleosomal DNA fragmentation. Furthermore, a caspase-8 inhibitor, IETD-fmk, blocked loss of mitochondrial membrane potential and apoptosis. These findings suggested that nonylphenol induced apoptosis of Jurkat cells by caspase-8 dependent mechanisms.
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Affiliation(s)
- Genhong Yao
- Department of Transfusion & the Postdoctoral Workstation, Jinling Hospital, Medical School, Nanjing University, PR China.
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18
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Li J, Wang J, Zeng Y. Peripheral benzodiazepine receptor ligand, PK11195 induces mitochondria cytochrome c release and dissipation of mitochondria potential via induction of mitochondria permeability transition. Eur J Pharmacol 2007; 560:117-22. [PMID: 17291492 DOI: 10.1016/j.ejphar.2006.12.027] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Revised: 12/12/2006] [Accepted: 12/18/2006] [Indexed: 10/23/2022]
Abstract
Mitochondrial permeability transition pore plays an important role in the processes of cell apoptosis and necrosis. The peripheral benzodiazepine receptor, a mitochondria outer-membrane protein, is involved in the regulation of mitochondrial permeability transition. In the present study, we test if PK11195, a peripheral benzodiazepine receptor ligand, can lead to the opening of mitochondrial permeability transition pores, and subsequently causes mitochondria cytochrome c loss and mitochondria uncoupling. In isolated cardiac mitochondria, PK11195 (50, 100, 200 microM) caused a dose-dependent mitochondrial swelling, cytochrome c loss, and the dissipation of mitochondrial potential. Cyclosporin A (0.2 microM), a specific inhibitor of mitochondrial permeability transition, completely prevented the mitochondrial swelling induced by PK11195, and maintained the cytochrome c content and membrane potential. These data suggest that peripheral benzodiazepine receptor ligand, PK11195 caused mitochondrial uncoupling and cytochrome c loss via induction of mitochondrial permeability transition.
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Affiliation(s)
- Jingyuan Li
- Department of Anesthesiology, the First Affiliated Hospital, China Medical University, Shenyang 110001, China.
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19
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Garg V, Hu K. Protein kinase C isoform-dependent modulation of ATP-sensitive K+ channels in mitochondrial inner membrane. Am J Physiol Heart Circ Physiol 2007; 293:H322-32. [PMID: 17351068 DOI: 10.1152/ajpheart.01035.2006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The ATP-sensitive K(+) (K(ATP)) channels in both sarcolemmal (sarcK(ATP)) and mitochondrial inner membrane (mitoK(ATP)) are the critical mediators in cellular protection of ischemic preconditioning (IPC). Whereas cardiac sarcK(ATP) contains Kir6.2 and sulfonylurea receptor (SUR)2A, the molecular identity of mitoK(ATP) remains elusive. In the present study, we tested the hypothesis that protein kinase C (PKC) may promote import of Kir6.2-containing K(ATP) into mitochondria. Fluorescence imaging of isolated mitochondria from both rat adult cardiomyocytes and COS-7 cells expressing recombinant Kir6.2/SUR2A showed that Kir6.2-containing K(ATP) channels were localized in mitochondria and this mitochondrial localization was significantly increased by PKC activation with phorbol 12-myristate 13-acetate (PMA). Fluorescence resonance energy transfer microscopy further revealed that a significant number of Kir6.2-containing K(ATP) channels were localized in mitochondrial inner membrane after PKC activation. These results were supported by Western blotting showing that the Kir6.2 protein level in mitochondria from COS-7 cells transfected with Kir6.2/SUR2A was enhanced after PMA treatment and this increase was inhibited by the selective PKC inhibitor chelerythrine. Furthermore, functional analysis indicated that the number of functional K(ATP) channels in mitochondria was significantly increased by PMA, as shown by K(ATP)-dependent decrease in mitochondrial membrane potential in COS-7 cells transfected with Kir6.2/SUR2A but not empty vector. Importantly, PKC-mediated increase in mitochondrial Kir6.2-containing K(ATP) channels was blocked by a selective PKCepsilon inhibitor peptide in both COS-7 cells and cardiomyocytes. We conclude that the K(ATP) channel pore-forming subunit Kir6.2 is indeed localized in mitochondria and that the Kir6.2 content in mitochondria is increased by activation of PKCepsilon. PKC isoform-regulated mitochondrial import of K(ATP) channels may have significant implication in cardioprotection of IPC.
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Affiliation(s)
- Vivek Garg
- Division of Pharmacology, College of Pharmacy, Ohio State University, 500 W. 12th Avenue, Columbus, OH 43210, USA
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20
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Choi JS, Shin S, Jin YH, Yim H, Koo KT, Chun KH, Oh YT, Lee WH, Lee SK. Cyclin-dependent protein kinase 2 activity is required for mitochondrial translocation of Bax and disruption of mitochondrial transmembrane potential during etoposide-induced apoptosis. Apoptosis 2007; 12:1229-41. [PMID: 17252195 DOI: 10.1007/s10495-006-0047-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Previous studies have suggested that upregulation of Cyclin A-dependent protein kinase 2 (Cdk2) activity is an essential event in apoptotic progression and the mitochondrial permeability transition in human cancer cells. Here, we show that upregulated Cyclin A/Cdk2 activity precedes the proteolytic cleavage of PARP and is correlated with the mitochondrial translocation of Bax and the loss of mitochondrial transmembrane potential (Deltapsim) during etoposide-induced apoptosis in human cervical adenocarcinoma (HeLa) cells. Etoposide-induced apoptotic cell death is efficiently prevented in cells that overexpress a dominant negative mutant of Cdk2 (Cdk2-dn) or p21(WAF1/CIP1), a specific Cdk inhibitor. Conversely, apoptotic cell death is promoted in Cyclin A-expressing cells. Disruption of the mitochondrial transmembrane potential in etoposide-induced cells is prevented in cells that overexpress Cdk2-dn or p21(WAF1/CIP1), while this transition is prominently promoted in Cyclin A-expressing cells. We screened for mitochondrial Cdk2 targets in the etoposide-induced cells and found that the mitochondrial level of Bax is elevated by more than three fold in etoposide-treated cells and this elevation is effectively prevented in cells expressing Cdk2-dn under the same conditions. Thus, we suggest that Cdk2 activity is involved in the mitochondrial translocation of Bax, which plays an important role in the mitochondrial membrane permeability transition during apoptotic progression.
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Affiliation(s)
- Joon-Seok Choi
- Division of Pharmaceutical Biosciences, College of Pharmacy and The Research Institute for Pharmaceutical Sciences, Seoul National University, Seoul, 151-742, Korea
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21
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Nervina JM, Magyar CE, Pirih FQ, Tetradis S. PGC-1alpha is induced by parathyroid hormone and coactivates Nurr1-mediated promoter activity in osteoblasts. Bone 2006; 39:1018-1025. [PMID: 16765661 DOI: 10.1016/j.bone.2006.04.023] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Revised: 04/13/2006] [Accepted: 04/20/2006] [Indexed: 11/25/2022]
Abstract
Parathyroid hormone (PTH) potently activates cAMP-protein kinase A (PKA)-driven molecular cascades in osteoblasts. The NR4A/NGFI-B orphan nuclear receptor (NR) Nurr1 is a PTH-induced, cAMP-responsive primary response gene (PRG) that transactivates osteocalcin (Ocn) expression through a putative NGFI-B response element (NBRE) in the proximal promoter. As a true orphan NR, Nurr1's expression level and coactivator recruitment regulate its transactivation capacity. We postulated that Nurr1's induction through cAMP-PKA signaling might favor a coactivator that is likewise cAMP-dependent. A possible candidate is the cAMP-inducible coactivator PPARgamma coactivator-1alpha (PGC-1alpha). We hypothesize that PGC-1alpha is a PTH-induced PRG that synergizes with Nurr1 to induce target gene transcription in osteoblasts. We show that 10 nM PTH for 2 h maximally induced PGC-1alpha mRNA in primary mouse osteoblasts (MOBs) and calvariae. Selective signaling agonists and antagonists demonstrated that PTH induced PGC-1alpha mRNA primarily through the cAMP-PKA pathway. Protein synthesis inhibition sustained PTH-induced PGC-1alpha expression. PGC-1alpha enhanced Nurr1-induced transactivation of a consensus 3xNBRE-luciferase construct and the rat (-1050)Ocn promoter-luciferase construct from 3.7- to 9.6- and 10.1-fold, respectively. This synergy required Nurr1-DNA binding, since a mutation of the Ocn promoter NBRE abolished both Nurr1- and Nurr1-PGC-1alpha-induced transactivation. Using GST pull-down assays, PGC-1alpha directly interacted with in vitro-generated and nuclear Nurr1. We conclude that PGC-1alpha is a PTH-induced, cAMP-dependent PRG that directly synergizes with Nurr1 to transactivate target genes in osteoblasts. Taken together with published data, our findings suggest that Nurr1 and PGC-1alpha may be pivotal mediators of cAMP-induced osteoblast gene expression and osteoblast function.
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Affiliation(s)
- Jeanne M Nervina
- Section of Orthodontics, UCLA School of Dentistry, Los Angeles, CA 90095, USA
| | - Clara E Magyar
- Division of Diagnostic and Surgical Sciences, UCLA School of Dentistry, Los Angeles, CA 90095, USA
| | - Flavia Q Pirih
- Division of Diagnostic and Surgical Sciences, UCLA School of Dentistry, Los Angeles, CA 90095, USA
| | - Sotirios Tetradis
- Division of Diagnostic and Surgical Sciences, UCLA School of Dentistry, Los Angeles, CA 90095, USA; UCLA Molecular Biology Institute, Los Angeles, CA 90095, USA.
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22
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Tammaro S, Simoniello P, Filosa S, Motta CM. Block of mitochondrial apoptotic pathways in lizard ovarian follicle cells as an adaptation to their nurse function. Cell Tissue Res 2006; 327:625-35. [PMID: 17036231 DOI: 10.1007/s00441-006-0256-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2005] [Accepted: 05/23/2006] [Indexed: 11/25/2022]
Abstract
Pyriforms are ovarian follicle nurse cells that undergo apoptosis at the end of previtellogenesis and are completely eliminated by the epithelium. This event is accompanied by the active transfer of organelles and macromolecules to the oocyte via an intercellular bridge. Since it would be a nonsense for damaged mitochondria to reach the oocyte, we have postulated that pyriform cells have adapted their apoptotic machinery to prevent mitochondrial degradation. To verify this hypothesis, we have studied mitochondrial morphology and functionality during follicle cell regression. Cytological and biochemical evidence indicates that mitochondria in pyriforms maintain their size, organization and membrane potential. This clearly indicates that they are not involved in apoptosis signalling/progression. This block would favour both the oocyte, by increasing the pool of organelles available from follicle cells, and also the regressing pyriforms, by maintaining the energy resources required for completion of their nurse function. The block is probably attributable to an over-expression of Bcl-2 and might be carried out by sequestering cytochrome c inside the organelles. As demonstrated by in vitro experiments, the mitochondrial apoptosis pathway can be activated by stress induction, such as serum deprivation, but not following physiological pro-apoptotic signalling, such as treatment with gonadotrophin-releasing hormone.
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Affiliation(s)
- Stefania Tammaro
- Dipartimento delle Scienze Biologiche, Section of Evolutionary and Comparative Biology, University of Naples Federico II, 80134 Naples, Italy
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23
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Yao G, Yang L, Hu Y, Liang J, Liang J, Hou Y. Nonylphenol-induced thymocyte apoptosis involved caspase-3 activation and mitochondrial depolarization. Mol Immunol 2006; 43:915-26. [PMID: 16046237 DOI: 10.1016/j.molimm.2005.06.031] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2005] [Indexed: 11/15/2022]
Abstract
Although the effect of 4-nonylphenol on cells of immune system have long been recognized, little is known about the effect of 4-nonylphenol on the induction of apoptosis and related signaling events in the lymphoid cells. In the present study, we used cultured thymocytes of mice to investigate the ability of 4-nonylphenol to induce the apoptosis of thymocytes and to explore the role of signal transduction pathway leading to apoptosis. The results showed that the cytotoxic effects of 4-nonyphenol involved DNA fragmentation (DNA ladder), characteristic of apoptosis. Staining of 4-nonyphenol-treated thymocytes with DNA-binding fluorochrome Hoechst 33258 showed the typical apoptotic nuclei condensation and fragmentation of chromatin. The rates of apoptosis of the 4-nonylphenol-treated thymocytes increased significantly at 4 and 6 h, which were determined by analysis of hypodiploid cells and FITC-Annexin V and PI double staining. Flow cytometer analysis also revealed that the loss of mitochondrial membrane potential and increased activity of caspase-3 occurred concomitantly with the onset of 4-nonyphenol-induced apoptosis. Furthermore, a caspase-3 inhibitor, z-DEVD-fmk protected thymocytes from apoptosis induced by 4-nonyphenol. These results suggest that 4-nonylphenol induces thymocyte apoptosis via caspase-3 activation and mitochondrial depolarization.
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Affiliation(s)
- Genhong Yao
- Jiangsu Province Key Lab of Reproductive Medicine, Nanjing Medical University, Nanjing 210029, China
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24
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Synak A, Bojarski P. Transition-moment directions of selected carbocyanines from emission anisotropy and linear dichroism measurements in uniaxially stretched polymer films. Chem Phys Lett 2005. [DOI: 10.1016/j.cplett.2005.09.097] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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25
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Abstract
Recent advances have highlighted a synchronous coordination of osteoblast and osteoclast activity, whereby, the osteoblast collates all signals applied to the bone and activates osteoclastic resorption. The resorption of the bone and its matrix then releases growth factors held within the matrix (bone morphogenetic proteins, insulin-like growth factors and transforming growth factors) which then stimulate the osteoblast to lay down new osteoid. In healthy adults there is a balance between bone deposition and bone loss and there is no net gain or loss, and the amount of calcium (Ca2+) ingested in the diet is equal to that which is excreted. In the early stages of life, the emphasis is on bone building and more Ca2+ is retained from the diet and more bone deposited as the skeleton matures. As we age, and, in particular in postmenopausal women, the osteoclastic activity outweighs the bone deposition and the patient loses bone becoming osteoporotic. The focus of the work reported here was to identify and dissect the various cytosolic intracellular signalling pathways within osteoblasts and establish the importance of each under different physiological conditions. In brief, two basic signalling pathways exist; one is linked with a seven transmembrane spanning protein and specific receptors for ligands (the G protein linked pathways) and one pathway is linked with protein phosphorylation especially of the tyrosine kinases. In general, G protein activity is associated with endocrine ligands such as parathyroid hormone (PTH) and (calcitonin has been linked with tyrosine kinase activity) tyrosine kinase activity is linked with adhesion of osteoblasts and recognition of the substrate to which they are attached. Our specific areas of interest are the ways in which Ca2+ activity within the cell is modified and used as a signal for further activation and possibly differential gene activation.
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Affiliation(s)
- F McDonald
- GKT Dental Institute, Floor 22, Guys Tower, St Thomas Street, London SE1 9RT
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26
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Albitar M, Manshouri T, Shen Y, Liu D, Beran M, Kantarjian HM, Rogers A, Jilani I, Lin CW, Pierce S, Freireich EJ, Estey EH. Myelodysplastic syndrome is not merely "preleukemia". Blood 2002; 100:791-8. [PMID: 12130488 DOI: 10.1182/blood.v100.3.791] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Myelodysplastic syndrome (MDS) is a disease characterized by ineffective hematopoiesis. There are significant biologic and clinical differences between MDS and acute myeloid leukemia (AML). We studied a cohort of 802 patients, 279 (35%) with newly diagnosed MDS and 523 (65%) with newly diagnosed AML, and compared clinical and biologic characteristics of the 2 groups. Complete clinical and cytogenetic data were available on all patients, and a subgroup of patients was studied for apoptosis, angiogenesis, proliferation, and growth factors. Our results demonstrate that MDS is a discrete entity that is different from AML and is characterized primarily by increased apoptosis in early and mature hematopoietic cells. Using cell sorting and loss of heterozygosity, we demonstrate that the leukemic cells from MDS patients are capable of differentiation into mature myeloid cells and monocytes. We also demonstrate that there is a significant overlap between AML and MDS when MDS is defined on the basis of an arbitrary percentage of blasts of 20% or 30%. These data suggest that despite similarities between AML and MDS in their responses to treatment and outcomes, MDS is biologically and clinically different from AML and should not be considered an early phase of AML. The data indicate that MDS must be better defined on the basis of its biology rather than the percentage of blasts; further, the data suggest that there is a need to develop therapeutic approaches that specifically address the biologic abnormalities of MDS.
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Affiliation(s)
- Maher Albitar
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston 77030-4095, USA.
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27
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Cazzalini O, Lazzè MC, Iamele L, Stivala LA, Bianchi L, Vaghi P, Cornaglia A, Calligaro A, Curti D, Alessandrini A, Prosperi E, Vannini V. Early effects of AZT on mitochondrial functions in the absence of mitochondrial DNA depletion in rat myotubes. Biochem Pharmacol 2001; 62:893-902. [PMID: 11543724 DOI: 10.1016/s0006-2952(01)00713-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Zidovudine (AZT) is a potent inhibitor of human immunodeficiency virus (HIV) replication. In humans, as well as in animal models, long-term treatment with AZT induces a severe myopathy characterised by structural and functional alterations of mitochondria associated with depletion of mitochondrial DNA (mtDNA). In the present work, we compared the effects induced by AZT on mitochondria upon short- or long-term treatments of cultured rat myotubes. Morphological alterations were investigated by electron microscopy, and mtDNA depletion and deletions were analysed by Southern blot. Mitochondrial membrane potential was determined after JC-1 staining by laser-scanning confocal microscopy in whole cells, and by flow cytometry in isolated muscle mitochondria. We found that the early effects of AZT on mitochondrial functions were a marked, yet reversible reduction in mitochondrial membrane potential, in the absence of any effect on mtDNA. The long-term treatment, in addition to mitochondrial membrane potential alterations, induced morphological changes in mitochondria, and a remarkable reduction in the amount of mtDNA, without any significant evidence of mtDNA deletions. In both treatments, a block of the spontaneous contraction of myotubes was observed. To study in more detail the early effects induced by AZT, the ability of the drug to interact with cardiolipin, an important component of internal mitochondrial membrane, was investigated by atomic force microscopy (AFM) in an artificial membrane model system. The results suggest that the primary effects of AZT may be related to a physical interference with the membrane structure leading to a consequent modification of its physical characteristics.
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Affiliation(s)
- O Cazzalini
- Dipartimento di Medicina sperimentale, sez. Patologia generale C.Golgi , P.zza Botta 10; I-27100, Pavia, Italy.
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28
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Xu M, Wang Y, Ayub A, Ashraf M. Mitochondrial K(ATP) channel activation reduces anoxic injury by restoring mitochondrial membrane potential. Am J Physiol Heart Circ Physiol 2001; 281:H1295-303. [PMID: 11514300 DOI: 10.1152/ajpheart.2001.281.3.h1295] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mitochondrial membrane potential (DeltaPsi(m)) is severely compromised in the myocardium after ischemia-reperfusion and triggers apoptotic events leading to cell demise. This study tests the hypothesis that mitochondrial ATP-sensitive K(+) (mitoK(ATP)) channel activation prevents the collapse of DeltaPsi(m) in myocytes during anoxia-reoxygenation (A-R) and is responsible for cell protection via inhibition of apoptosis. After 3-h anoxia and 2-h reoxygenation, the cultured myocytes underwent extensive damage, as evidenced by decreased cell viability, compromised membrane permeability, increased apoptosis, and decreased ATP concentration. Mitochondria in A-R myocytes were swollen and fuzzy as shown after staining with Mito Tracker Orange CMTMRos and in an electron microscope and exhibited a collapsed DeltaPsi(m), as monitored by 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide (JC-1). Cytochrome c was released from mitochondria into the cytosol as demonstrated by cytochrome c immunostaining. Activation of mitoK(ATP) channel with diazoxide (100 micromol/l) resulted in a significant protection against mitochondrial damage, ATP depletion, cytochrome c loss, and stabilized DeltaPsi(m). This protection was blocked by 5-hydroxydecanoate (500 micromol/l), a mitoK(ATP) channel-selective inhibitor, but not by HMR-1098 (30 micromol/l), a putative sarcolemmal K(ATP) channel-selective inhibitor. Dissipation of DeltaPsi(m) also leads to opening of mitochondrial permeability transition pore, which was prevented by cyclosporin A. The data support the hypothesis that A-R disrupts DeltaPsi(m) and induces apoptosis, which are prevented by the activation of the mitoK(ATP) channel. This further emphasizes the therapeutic significance of mitoK(ATP) channel agonists in the prevention of ischemia-reperfusion cell injury.
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Affiliation(s)
- M Xu
- Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio 45267-0529, USA
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Affiliation(s)
- A Cossarizza
- Department of Biomedical Sciences, University of Modena, Italy
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Komarova SV, Ataullakhanov FI, Globus RK. Bioenergetics and mitochondrial transmembrane potential during differentiation of cultured osteoblasts. Am J Physiol Cell Physiol 2000; 279:C1220-9. [PMID: 11003602 DOI: 10.1152/ajpcell.2000.279.4.c1220] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To evaluate the relationship between osteoblast differentiation and bioenergetics, cultured primary osteoblasts from fetal rat calvaria were grown in medium supplemented with ascorbate to induce differentiation. Before ascorbate treatment, the rate of glucose consumption was 320 nmol. h(-1). 10(6) cells(-1), respiration was 40 nmol. h(-1). 10(6) cells(-1), and the ratio of lactate production to glucose consumption was approximately 2, indicating that glycolysis was the main energy source for immature osteoblasts. Ascorbate treatment for 14 days led to a fourfold increase in respiration, a threefold increase in ATP production, and a fivefold increase in ATP content compared with that shown in immature cells. Confocal imaging of mitochondria stained with a transmembrane potential-sensitive vital dye showed that mature cells possessed abundant amounts of high-transmembrane-potential mitochondria, which were concentrated near the culture medium-facing surface. Acute treatment of mature osteoblasts with metabolic inhibitors showed that the rate of glycolysis rose to maintain the cellular energy supply constant. Thus progressive differentiation coincided with changes in cellular metabolism and mitochondrial activity, which are likely to play key roles in osteoblast function.
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Affiliation(s)
- S V Komarova
- Life Sciences Division, NASA Ames Research Center, Moffett Field, California 94035-1000, USA
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Gravance CG, Garner DL, Baumber J, Ball BA. Assessment of equine sperm mitochondrial function using JC-1. Theriogenology 2000; 53:1691-703. [PMID: 10968415 DOI: 10.1016/s0093-691x(00)00308-3] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The fluorescent carbocyanine dye, JC-1, labels mitochondria with high membrane potential orange and mitochondria with low membrane potential green. Evaluation of mitochondrial membrane potential with JC-1 has been used in a variety of cell types, including bull spermatozoa; however, JC-1 staining has not yet been reported for equine spermatozoa. The aim of this study was to apply JC-1 staining and assessment by flow cytometry or a fluorescence microplate reader for evaluation of mitochondrial function of equine spermatozoa. Six ejaculates from four stallions were collected and centrifuged through a Percoll gradient (PERC). Spermatozoa were resuspended to 25 x 10(6) cells/mL, samples were split, and one sample was repeatedly flash frozen (FF) in LN2 and thawed. The following gradients of PERC:FF were prepared: 100:0 (100), 75:25(75), 50:50 (50), 25:75 (25) and 0:100 (0). Samples were stained with 2.0 microM JC-1 and assessed for staining by flow cytometry and by a fluorescence microplate reader. A total of 10,000 gated events was analyzed per sample with flow cytometry. The mean percentage of cells staining orange for the 100, 75, 50, 25 and 0 treatments was 92.5, 72.8, 53.4, 27.3 and 7.3, respectively. The expected percentage of spermatozoa forming JC-1 aggregates was correlated with the actual percentage of orange labeled sperm cells determined by flow cytometry (r2=0.98). Conversely, JC-1 monomer formation was negatively correlated with expected mitochondrial membrane potential (r2=-0.98). The blank corrected orange fluorescence, assessed by microplate assay, was significantly (P<0.0001) correlated with the expected (r2=0.49) and with the flow cytometric (r2=0.50) determination of percentage of spermatozoa with mitochondria of high membrane potential. Total orange and orange:green fluorescence was also correlated with mitochondrial function. These results indicate that JC-1 staining can accurately detect changes in mitochondrial membrane potential of equine spermatozoa. The relative fluorescence of JC-1 labeling patterns of equine spermatozoa can be accurately and objectively determined by flow cytometry and by a fluorescence microplate reader assay.
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Affiliation(s)
- C G Gravance
- Department of Population, Health and Reproduction, University of California, Davis, USA
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Dispersyn G, Nuydens R, Connors R, Borgers M, Geerts H. Bcl-2 protects against FCCP-induced apoptosis and mitochondrial membrane potential depolarization in PC12 cells. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1428:357-71. [PMID: 10434055 DOI: 10.1016/s0304-4165(99)00073-2] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
This report addresses the relation between Bcl-2 and mitochondrial membrane potential (DeltaPsi(m)) in apoptotic cell death. Rat pheochromocytoma (PC12) cells are differentiated into neuron-like cells with nerve growth factor (NGF). It is known that Bcl-2 can attenuate apoptosis induced by deprivation of neurotrophic factor. The protective effect of Bcl-2 has been correlated with preservation of DeltaPsi(m). Protonophores, such as carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP), collapse the proton gradient across the mitochondrial inner membrane, resulting in a complete abolition of the mitochondrial membrane potential. Based on the analysis of morphology, of phosphatidylserine exposure and of nuclear fragmentation we conclude that FCCP induces apoptosis in PC12 cells, which can be prevented by overexpression of Bcl-2. To determine whether the cytoprotective effect of Bcl-2 is due to stabilization of DeltaPsi(m), we investigated the effect of Bcl-2 on changes in DeltaPsi(m), induced by FCCP in PC12 cells. We showed that treatment with FCCP induced a reduction in DeltaPsi(m), as assessed with the lipophilic cationic membrane potential-sensitive dye JC-1, and that Bcl-2 protects against FCCP-induced changes in NGF differentiated PC12 cells. Our data indicate that Bcl-2 protects against FCCP-induced cell death by stabilizing DeltaPsi(m).
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Affiliation(s)
- G Dispersyn
- Department of Biochemistry, University of Antwerp, Antwerp, Belgium
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Minamikawa T, Williams DA, Bowser DN, Nagley P. Mitochondrial permeability transition and swelling can occur reversibly without inducing cell death in intact human cells. Exp Cell Res 1999; 246:26-37. [PMID: 9882512 DOI: 10.1006/excr.1998.4290] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Severe disruption of mitochondrial function is generally considered to provide a powerful trigger for apoptosis in mammalian cells. We report here that intact cells may undergo the mitochondrial permeability transition and mitochondria swell in a fully reversible manner, without inducing cell death. Cultured human osteosarcoma cells (143B TK-) stained with JC-1, MitoTracker dyes, or calcein plus Co2+ were imaged by confocal microscopy to visualize changes of mitochondrial membrane potential (DeltaPsim), morphology, and permeability transition, respectively, during treatment with a protonophore, carbonyl cyanide m-chlorophenylhydrazone (CCCP). Cells rapidly exhibited mitochondrial permeability transition and swelling after addition of CCCP, but the swelling subsided within hours, leaving mitochondria that appeared in punctate form, not filamentous as before CCCP treatment. Cyclosporin A impeded the permeability transition and swelling, although complete inhibition was not observed. Cells survived the dissipation of DeltaPsim by CCCP for up to 6 h without developing any obvious cell damage or signs of apoptosis. With the restoration of DeltaPsim after removal of CCCP (following 6 h of CCCP treatment), permeability transition pores were closed. These results suggest that none of the following events represent a point of no return in the process of apoptotic cell death: loss of DeltaPsim, mitochondrial permeability transition, or mitochondrial swelling.
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Affiliation(s)
- T Minamikawa
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, 3168, Australia
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