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Tu YC, Chao FY, Tsai MF. Mechanisms of dual modulatory effects of spermine on the mitochondrial calcium uniporter complex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.06.543936. [PMID: 37333420 PMCID: PMC10274775 DOI: 10.1101/2023.06.06.543936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
The mitochondrial Ca 2 + uniporter mediates the crucial cellular process of mitochondrial Ca 2 + uptake, which regulates cell bioenergetics, intracellular Ca 2 + signaling, and cell death initiation. The uniporter contains the pore-forming MCU subunit, an EMRE protein that binds to MCU, and the regulatory MICU1 subunit, which can dimerize with MICU1 or MICU2 and under resting cellular [Ca 2 + ] occludes the MCU pore. It has been known for decades that spermine, which is ubiquitously present in animal cells, can enhance mitochondrial Ca 2 + uptake, but the underlying mechanisms remain unclear. Here, we show that spermine exerts dual modulatory effects on the uniporter. In physiological concentrations of spermine, it enhances uniporter activity by breaking the physical interactions between MCU and the MICU1-containing dimers to allow the uniporter to constitutively take up Ca 2 + even in low [Ca 2 + ] conditions. This potentiation effect does not require MICU2 or the EF-hand motifs in MICU1. When [spermine] rises to millimolar levels, it inhibits the uniporter by targeting the pore region in a MICU-independent manner. The MICU1-dependent spermine potentiation mechanism proposed here, along with our previous finding that cardiac mitochondria have very low MICU1, can explain the puzzling observation in the literature that mitochondria in the heart show no response to spermine.
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Affiliation(s)
- Yung-Chi Tu
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Fan-Yi Chao
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Ming-Feng Tsai
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
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Tantak MP, Sekhar V, Tao X, Zhai RG, Phanstiel O. Development of a Redox-Sensitive Spermine Prodrug for the Potential Treatment of Snyder Robinson Syndrome. J Med Chem 2021; 64:15593-15607. [PMID: 34695351 DOI: 10.1021/acs.jmedchem.1c00419] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Snyder Robinson Syndrome (SRS) is a rare disease associated with a defective spermine synthase gene and low intracellular spermine levels. In this study, a spermine replacement therapy was developed using a spermine prodrug that enters cells via the polyamine transport system. The prodrug was comprised of three components: a redox-sensitive quinone "trigger", a "trimethyl lock (TML)" aryl "release mechanism", and spermine. The presence of spermine in the design facilitated uptake by the polyamine transport system. The quinone-TML motifs provided a redox-sensitive agent, which upon intracellular reduction generated a hydroquinone, which underwent intramolecular cyclization to release free spermine and a lactone byproduct. Rewardingly, most SRS fibroblasts treated with the prodrug revealed a significant increase in intracellular spermine. Administering the spermine prodrug through feeding in a Drosophila model of SRS showed significant beneficial effects. In summary, a spermine prodrug is developed and provides a lead compound for future spermine replacement therapy experiments.
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Affiliation(s)
- Mukund P Tantak
- Department of Medical Education, College of Medicine, University of Central Florida, 12722 Research Parkway, Orlando, Florida 32826-3227, United States
| | - Vandana Sekhar
- Department of Medical Education, College of Medicine, University of Central Florida, 12722 Research Parkway, Orlando, Florida 32826-3227, United States
| | - Xianzun Tao
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, 1600 NW 10th Ave, Miami, Florida 33136, United States
| | - R Grace Zhai
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, 1600 NW 10th Ave, Miami, Florida 33136, United States
| | - Otto Phanstiel
- Department of Medical Education, College of Medicine, University of Central Florida, 12722 Research Parkway, Orlando, Florida 32826-3227, United States
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Miyake M, Minami T, Maruyama M, Mukai T, Higaki K. Spermine with Sodium Taurocholate Enhances Pulmonary Absorption of Macromolecules in Rats. J Pharm Sci 2021; 110:3464-3470. [PMID: 34118254 DOI: 10.1016/j.xphs.2021.06.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 06/05/2021] [Accepted: 06/05/2021] [Indexed: 11/17/2022]
Abstract
The improvement effect of the combined use of spermine (SPM), a polyamine, with sodium taurocholate (STC) on the pulmonary drug absorption was investigated utilizing poorly absorbable drugs with various molecular sizes in rats. The pulmonary absorption of rebamipide, a low molecular but poorly absorbable drug after oral administration, was significantly improved by the combined use of SPM with STC (SPM-STC formulation), while poly- L-lysine did not show a significant change in rebamipide absorption from the lungs. Furthermore, the safety of the SPM-STC formulation for the lungs was assessed in rats by the histopathological study and any local toxicity was not observed while poly-L-lysine, a typical chemical causing the toxicity for the epithelial cells, provided several histopathological changes. In addition, the SPM-STC formulation significantly improved the pulmonary absorption of fluorescein isothiocyanate dextran 4 (FD-4, Mw ca 4000) and interferon-α (IFN-α, Mw ca 25,000) as well. Our present results clearly indicated that the SPM-STC formulation significantly improved the pulmonary absorption of poorly absorbable small and large molecular drugs without any harmful effects on the lungs. Therefore, the SPM-STC formulation would be a useful one for the pulmonary absorption of drugs, specifically macromolecular ones, which are very difficult to be absorbed after oral administration.
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Affiliation(s)
- Masateru Miyake
- BA Project, Formulation Research Institute, Otsuka Pharmaceutical Co. Ltd., 224-18 Ebisuno Hiraishi Kawauchi-cho, Tokushima 771-0182, Japan; Medical Safety Section, Pharmacovigilance Department, Otsuka Pharmaceutical Co. Ltd., 3-2-27, Otedori, Chuo-ku, Osaka 540-0021, Japan.
| | - Takanori Minami
- Histopathology Research Office, Department of Toxicology, Tokushima Research Institute, Otsuka Pharmaceutical Co., Ltd., 463-10 Kagasuno, Kawauchi-cho, Tokushima 771-0192, Japan
| | - Masato Maruyama
- Department of Pharmaceutics, Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, kita-ku, Okayama 700-8530, Japan
| | - Tadashi Mukai
- BA Project, Formulation Research Institute, Otsuka Pharmaceutical Co. Ltd., 224-18 Ebisuno Hiraishi Kawauchi-cho, Tokushima 771-0182, Japan
| | - Kazutaka Higaki
- Department of Pharmaceutics, Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, kita-ku, Okayama 700-8530, Japan
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Rodriguez-Armenta C, Reyes-Zamora O, De la Re-Vega E, Sanchez-Paz A, Mendoza-Cano F, Mendez-Romero O, Gonzalez-Rios H, Muhlia-Almazan A. Adaptive mitochondrial response of the whiteleg shrimp Litopenaeus vannamei to environmental challenges and pathogens. J Comp Physiol B 2021; 191:629-644. [PMID: 33895873 DOI: 10.1007/s00360-021-01369-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 03/03/2021] [Accepted: 04/13/2021] [Indexed: 01/01/2023]
Abstract
In most eukaryotic organisms, mitochondrial uncoupling mechanisms control ATP synthesis and reactive oxygen species production. One such mechanism is the permeability transition of the mitochondrial inner membrane. In mammals, ischemia-reperfusion events or viral diseases may induce ionic disturbances, such as calcium overload; this cation enters the mitochondria, thereby triggering the permeability transition. This phenomenon increases inner membrane permeability, affects transmembrane potential, promotes mitochondrial swelling, and induces apoptosis. Previous studies have found that the mitochondria of some crustaceans do not exhibit a calcium-regulated permeability transition. However, in the whiteleg shrimp Litopenaeus vannamei, contradictory evidence has prevented this phenomenon from being confirmed or rejected. Both the ability of L. vannamei mitochondria to take up large quantities of calcium through a putative mitochondrial calcium uniporter with conserved characteristics and permeability transition were investigated in this study by determining mitochondrial responses to cations overload. By measuring mitochondrial swelling and transmembrane potential, we investigated whether shrimp exposure to hypoxia-reoxygenation events or viral diseases may induce mitochondrial permeability transition. The results of this study demonstrate that shrimp mitochondria take up large quantities of calcium through a canonical mitochondrial calcium uniporter. Neither calcium nor other ions were observed to promote permeability transition. This phenomenon does not depend on the life cycle stage of shrimp, and it is not induced during hypoxia/reoxygenation events or in the presence of viral diseases. The absence of the permeability transition phenomenon and its adaptive meaning are discussed as a loss with biological advantages, possibly enabling organisms to survive under harsh environmental conditions.
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Affiliation(s)
- Chrystian Rodriguez-Armenta
- Centro de Investigacion en Alimentacion y Desarrollo, A.C., (CIAD), Carretera Gustavo Enrique Astiazaran Rosas 46, 83304, Hermosillo, Sonora, Mexico
| | - Orlando Reyes-Zamora
- Centro de Investigacion en Alimentacion y Desarrollo, A.C., (CIAD), Carretera Gustavo Enrique Astiazaran Rosas 46, 83304, Hermosillo, Sonora, Mexico
| | - Enrique De la Re-Vega
- Department of Scientific and Technological Research, Universidad de Sonora (DICTUS), 83000, Hermosillo, Sonora, Mexico
| | - Arturo Sanchez-Paz
- Laboratorio de Virologia. Centro de Investigaciones Biologicas del Noroeste S.C. (CIBNOR), Calle Hermosa 101, Col. Los Angeles, 83106, Hermosillo, Sonora, Mexico
| | - Fernando Mendoza-Cano
- Laboratorio de Virologia. Centro de Investigaciones Biologicas del Noroeste S.C. (CIBNOR), Calle Hermosa 101, Col. Los Angeles, 83106, Hermosillo, Sonora, Mexico
| | - Ofelia Mendez-Romero
- Centro de Investigacion en Alimentacion y Desarrollo, A.C., (CIAD), Carretera Gustavo Enrique Astiazaran Rosas 46, 83304, Hermosillo, Sonora, Mexico
| | - Humberto Gonzalez-Rios
- Centro de Investigacion en Alimentacion y Desarrollo, A.C., (CIAD), Carretera Gustavo Enrique Astiazaran Rosas 46, 83304, Hermosillo, Sonora, Mexico
| | - Adriana Muhlia-Almazan
- Centro de Investigacion en Alimentacion y Desarrollo, A.C., (CIAD), Carretera Gustavo Enrique Astiazaran Rosas 46, 83304, Hermosillo, Sonora, Mexico.
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Yamamoto A, Ukai H, Morishita M, Katsumi H. Approaches to improve intestinal and transmucosal absorption of peptide and protein drugs. Pharmacol Ther 2020; 211:107537. [DOI: 10.1016/j.pharmthera.2020.107537] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 03/08/2020] [Indexed: 12/14/2022]
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Schauwecker J, Bock M, Pohlig F, Mühlhofer H, Tübel J, von Eisenhart-Rothe R, Kirchhoff C. In vitro Growth Pattern of Primary Human Osteoblasts on Calcium Phosphate- and Polymethylmethacrylate-Based Bone Cement. Eur Surg Res 2017; 58:216-226. [PMID: 28494462 DOI: 10.1159/000470839] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 03/13/2017] [Indexed: 11/19/2022]
Abstract
BACKGROUND/PURPOSE Polymethylmethacrylate (PMMA) and calcium phosphate (Ca-P) cements are widely used for arthroplasty surgery and augmentation of bone defects. However, aseptic implant loosening in absence of wear-induced osteolysis indicates an unfavourable interaction between the cement surface and human osteoblasts. Our underlying hypothesis is that cement surfaces directly modify cell viability, proliferation rate, and cell differentiation. METHODS To test this hypothesis, we examined primary human osteoblasts harvested from six individuals. These cells were pooled and subsequently seeded directly on cement pellets prepared from Palacos® R, Palacos® R+G, and Norian® Drillable cements. After incubation for 24 and 72 h, cell viability, proliferation rate, apoptosis rate, and cell differentiation were analysed. RESULTS Upon cultivation of human osteoblasts on cement surfaces, we observed a significantly reduced cell viability and DNA content compared to the control. Analysis of the apoptosis rate revealed an increase for cells on Palacos R and Norian Drillable, but a significant decrease on Palacos R+G compared to the control. Regarding osteogenic differentiation, significantly lower values of alkaline phosphatase enzyme activity were identified for all cement surfaces after 24 and 72 h compared to cultivation on tissue culture plastic, serving as control. CONCLUSIONS In summary, these data suggest a limited biocompatibility of both PMMA and Ca-P cements, necessitating further research to reduce unfavourable cell-cement interactions and consequently extend implant survival.
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Affiliation(s)
- Johannes Schauwecker
- Department of Orthopaedic Surgery, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
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Meulenberg CJW, de Groot A, Westerink RHS, Vijverberg HPM. Organic solvent-induced changes in membrane geometry in human SH-SY5Y neuroblastoma cells - a common narcotic effect? Neurotoxicology 2016; 55:74-82. [PMID: 27235192 DOI: 10.1016/j.neuro.2016.05.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Revised: 05/11/2016] [Accepted: 05/20/2016] [Indexed: 10/21/2022]
Abstract
Exposure to organic solvents may cause narcotic effects. At the cellular level, these narcotic effects have been associated with a reduction in neuronal excitability caused by changes in membrane structure and function. In order to critically test whether changes in membrane geometry contribute to these narcotic effects, cultured human SH-SY5Y neuroblastoma cells have been exposed to selected organic solvents. The solvent-induced changes in cell membrane capacitance were investigated using the whole-cell patch clamp technique for real-time capacitance measurements. Exposure of SH-SY5Y cells to the cyclic hydrocarbons m-xylene, toluene, and cyclohexane caused a rapid and reversible increase of membrane capacitance. The aliphatic, nonpolar n-hexane did not cause a detectable change of whole-cell membrane capacitance, whereas the amphiphiles n-hexanol and n-hexylamine caused an increase of membrane capacitance and a concomitant reduction in membrane resistance. Despite a large difference in dielectric properties, the chlorinated hydrocarbons 1,1,2,2-tetrachoroethane and tetrachloroethylene caused a similar magnitude increase in membrane capacitance. The theory on membrane capacitance has been applied to deduce changes in membrane geometry caused by solvent partitioning. Although classical observations have shown that solvents increase the membrane capacitance per unit area of membrane, i.e., increase membrane thickness, the present results demonstrate that solvent partitioning predominantly leads to an increase in membrane surface area and to a lesser degree to an increase in membrane thickness. Moreover, the present results indicate that the physicochemical properties of each solvent are important determinants for its specific effects on membrane geometry. This implies that the hypothesis that solvent partitioning is associated with a common perturbation of membrane structure needs to be revisited and cannot account for the commonly observed narcotic effects of different organic solvents.
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Affiliation(s)
- Cécil J W Meulenberg
- Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, PO Box 80.177, NL 3508 TD Utrecht, The Netherlands.
| | - Aart de Groot
- Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, PO Box 80.177, NL 3508 TD Utrecht, The Netherlands
| | - Remco H S Westerink
- Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, PO Box 80.177, NL 3508 TD Utrecht, The Netherlands
| | - Henk P M Vijverberg
- Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, PO Box 80.177, NL 3508 TD Utrecht, The Netherlands
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9
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Abstract
PURPOSE Gentamicin is a widely employed antibiotic, but may reduce calcium uptake by eukaryotic cells. This study was conducted to determine whether gentamicin reduces calcification by porcine aortic valvular interstitial cells (pAVICs) grown in 2D culture, which is a common model for calcific aortic valve disease (CAVD). METHODS AND RESULTS The presence of gentamicin (up to 0.2 mM) in the medium of pAVICs cultured for 8 days significantly lowered calcification and alkaline phosphatase content in a dose-dependent manner compared to pAVICs cultured without gentamicin. Gentamicin also significantly increased cell proliferation and apoptosis at concentrations of 0.1-0.2 mM. Next, gentamicin was applied to previously calcified pAVIC cultures (grown for 8 days) to determine whether it could stop or reverse the calcification process. Daily application of gentamicin for 8 additional days significantly reduced calcification to below the pre-calcification levels. CONCLUSIONS These results confirm that gentamicin should be used cautiously with in vitro studies of calcification, and suggest that gentamicin may have the ability to reverse calcification by pAVICs. Given the nephrotoxicity and ototoxicity of this antibiotic, its clinical potential for the treatment of calcification in heart valves is limited. However, further investigation of the pathways through which gentamicin alters calcium uptake by valvular cells may provide insight into novel therapies for CAVD.
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Calì T, Ottolini D, Brini M. Mitochondrial Ca(2+) as a key regulator of mitochondrial activities. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 942:53-73. [PMID: 22399418 DOI: 10.1007/978-94-007-2869-1_3] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Mitochondria play a central role in cell biology, not only as producers of ATP but also as regulators of the Ca(2+) signal. The translocation by respiratory chain protein complexes of H(+) across the ion-impermeable inner membrane generates a very large H(+) electrochemical gradient that can be employed not only by the H(+) ATPase to run the endoergonic reaction of ADP phosphorylation, but also to accumulate cations into the matrix. Mitochondria can rapidly take up Ca(2+) through an electrogenic pathway, the uniporter, that acts to equilibrate Ca(2+) with its electrochemical gradient, and thus accumulates the cation into the matrix, and they can release it through two exchangers (with H(+) and Na(+), mostly expressed in non-excitable and excitable cells, respectively), that utilize the electrochemical gradient of the monovalent cations to prevent the attainment of electrical equilibrium.The uniporter, due to its low Ca(2+) affinity, demands high local Ca(2+) concentrations to work. In different cell systems these high Ca(2+) concentration microdomains are generated, upon cell stimulation, in proximity of the plasma membrane and the sarco/endoplasmic reticulum Ca(2+) channels.Recent work has revealed the central role of mitochondria in signal transduction pathways: evidence is accumulating that, by taking up Ca(2+), they not only modulate mitochondrial activities but also tune the cytosolic Ca(2+) signals and their related functions. This review analyses recent developments in the area of mitochondrial Ca(2+) signalling and attempts to summarize cell physiology aspects of the mitochondrial Ca(2+) transport machinery.
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Affiliation(s)
- Tito Calì
- Department of Comparative Biomedicine and Food Science, University of Padova, Padova, Italy
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11
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Grandinetti G, Ingle NP, Reineke TM. Interaction of poly(ethylenimine)-DNA polyplexes with mitochondria: implications for a mechanism of cytotoxicity. Mol Pharm 2011; 8:1709-19. [PMID: 21699201 DOI: 10.1021/mp200078n] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Poly(ethylenimine) (PEI) and PEI-based systems have been widely studied for use as nucleic acid delivery vehicles. However, many of these vehicles display high cytotoxicity, rendering them unfit for therapeutic use. By exploring the mechanisms that cause cytotoxicity, and through understanding structure-function relationships between polymers and intracellular interactions, nucleic acid delivery vehicles with precise intracellular properties can be tailored for specific function. Previous research has shown that PEI is able to depolarize mitochondria, but the exact mechanism as to how depolarization is induced remains elusive and therefore is the focus of the current study. Potential mechanisms for mitochondrial depolarization include direct mitochondrial membrane permeabilization by PEI or PEI polyplexes, activation of the mitochondrial permeability transition pore, and interference with mitochondrial membrane proton pumps, specifically Complex I of the electron transport chain and F(0)F(1)-ATPase. Herein, confocal microscopy and live cell imaging showed that PEI polyplexes do colocalize to some degree with mitochondria early in transfection, and the degree of colocalization increases over time. Cyclosporin a was used to prevent activation of the mitochondrial membrane permeability transition pore, and it was found that early in transfection cyclosporin a was unable to prevent the loss of mitochondrial membrane potential. Further studies done using rotenone and oligomycin to inhibit Complex I of the electron transport chain and F(0)F(1)-ATPase, respectively, indicate that both of these mitochondrial proton pumps are functioning during PEI transfection. Overall, we conclude that direct interaction between polyplexes and mitochondria may be the reason why mitochondrial function is impaired during PEI transfection.
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Affiliation(s)
- Giovanna Grandinetti
- Department of Chemistry & Macromolecules & Interfaces Institute, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, United States
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Yoon YG, Koob MD. Toward genetic transformation of mitochondria in mammalian cells using a recoded drug-resistant selection marker. J Genet Genomics 2011; 38:173-9. [PMID: 21530901 DOI: 10.1016/j.jgg.2011.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 03/07/2011] [Accepted: 03/10/2011] [Indexed: 01/04/2023]
Abstract
Due to technical difficulties, the genetic transformation of mitochondria in mammalian cells is still a challenge. In this report, we described our attempts to transform mammalian mitochondria with an engineered mitochondrial genome based on selection using a drug resistance gene. Because the standard drug-resistant neomycin phosphotransferase confers resistance to high concentrations of G418 when targeted to the mitochondria, we generated a recoded neomycin resistance gene that uses the mammalian mitochondrial genetic code to direct the synthesis of this protein in the mitochondria, but not in the nucleus (mitochondrial version). We also generated a universal version of the recoded neomycin resistance gene that allows synthesis of the drug-resistant proteins both in the mitochondria and nucleus. When we transfected these recoded neomycin resistance genes that were incorporated into the mouse mitochondrial genome clones into mouse tissue culture cells by electroporation, no DNA constructs were delivered into the mitochondria. We found that the universal version of the recoded neomycin resistance gene was expressed in the nucleus and thus conferred drug resistance to G418 selection, while the synthetic mitochondrial version of the gene produced no background drug-resistant cells from nuclear transformation. These recoded synthetic drug-resistant genes could be a useful tool for selecting mitochondrial genetic transformants as a precise technology for mitochondrial transformation is developed.
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Affiliation(s)
- Young Geol Yoon
- Mitochondria Hub Regulation Center and Department of Anatomy and Cell Biology, Dong-A University College of Medicine, 3-1 Dongdaesin-dong, Seo-gu, Busan 602-714, Republic of Korea.
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Wei AC, Liu T, Cortassa S, Winslow RL, O'Rourke B. Mitochondrial Ca2+ influx and efflux rates in guinea pig cardiac mitochondria: low and high affinity effects of cyclosporine A. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:1373-81. [PMID: 21362444 DOI: 10.1016/j.bbamcr.2011.02.012] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 02/14/2011] [Accepted: 02/17/2011] [Indexed: 12/12/2022]
Abstract
Ca(2+) plays a central role in energy supply and demand matching in cardiomyocytes by transmitting changes in excitation-contraction coupling to mitochondrial oxidative phosphorylation. Matrix Ca(2+) is controlled primarily by the mitochondrial Ca(2+) uniporter and the mitochondrial Na(+)/Ca(2+) exchanger, influencing NADH production through Ca(2+)-sensitive dehydrogenases in the Krebs cycle. In addition to the well-accepted role of the Ca(2+)-triggered mitochondrial permeability transition pore in cell death, it has been proposed that the permeability transition pore might also contribute to physiological mitochondrial Ca(2+) release. Here we selectively measure Ca(2+) influx rate through the mitochondrial Ca(2+) uniporter and Ca(2+) efflux rates through Na(+)-dependent and Na(+)-independent pathways in isolated guinea pig heart mitochondria in the presence or absence of inhibitors of mitochondrial Na(+)/Ca(2+) exchanger (CGP 37157) or the permeability transition pore (cyclosporine A). cyclosporine A suppressed the negative bioenergetic consequences (ΔΨ(m) loss, Ca(2+) release, NADH oxidation, swelling) of high extramitochondrial Ca(2+) additions, allowing mitochondria to tolerate total mitochondrial Ca(2+) loads of >400nmol/mg protein. For Ca(2+) pulses up to 15μM, Na(+)-independent Ca(2+) efflux through the permeability transition pore accounted for ~5% of the total Ca(2+) efflux rate compared to that mediated by the mitochondrial Na(+)/Ca(2+) exchanger (in 5mM Na(+)). Unexpectedly, we also observed that cyclosporine A inhibited mitochondrial Na(+)/Ca(2+) exchanger-mediated Ca(2+) efflux at higher concentrations (IC(50)=2μM) than those required to inhibit the permeability transition pore, with a maximal inhibition of ~40% at 10μM cyclosporine A, while having no effect on the mitochondrial Ca(2+) uniporter. The results suggest a possible alternative mechanism by which cyclosporine A could affect mitochondrial Ca(2+) load in cardiomyocytes, potentially explaining the paradoxical toxic effects of cyclosporine A at high concentrations. This article is part of a Special Issue entitled: Mitochondria and Cardioprotection.
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Affiliation(s)
- An-Chi Wei
- Department of Biomedical Engineering, Institute of Computational Medicine, The Johns Hopkins University, Baltimore MD 21205-2195, USA
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14
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Waldeck-Weiermair M, Duan X, Naghdi S, Khan MJ, Trenker M, Malli R, Graier WF. Uncoupling protein 3 adjusts mitochondrial Ca(2+) uptake to high and low Ca(2+) signals. Cell Calcium 2010; 48:288-301. [PMID: 21047682 PMCID: PMC2998676 DOI: 10.1016/j.ceca.2010.10.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Accepted: 10/07/2010] [Indexed: 12/12/2022]
Abstract
Uncoupling proteins 2 and 3 (UCP2/3) are essential for mitochondrial Ca2+ uptake but both proteins exhibit distinct activities in regard to the source and mode of Ca2+ mobilization. In the present work, structural determinants of their contribution to mitochondrial Ca2+ uptake were explored. Previous findings indicate the importance of the intermembrane loop 2 (IML2) for the contribution of UCP2/3. Thus, the IML2 of UCP2/3 was substituted by that of UCP1. These chimeras had no activity in mitochondrial uptake of intracellularly released Ca2+, while they mimicked the wild-type proteins by potentiating mitochondrial sequestration of entering Ca2+. Alignment of the IML2 sequences revealed that UCP1, UCP2 and UCP3 share a basic amino acid in positions 163, 164 and 167, while only UCP2 and UCP3 contain a second basic residue in positions 168 and 171, respectively. Accordingly, mutants of UCP3 in positions 167 and 171/172 were made. In permeabilized cells, these mutants exhibited distinct Ca2+ sensitivities in regard to mitochondrial Ca2+ sequestration. In intact cells, these mutants established different activities in mitochondrial uptake of either intracellularly released (UCP3R171,E172) or entering (UCP3R167) Ca2+. Our data demonstrate that distinct sites in the IML2 of UCP3 effect mitochondrial uptake of high and low Ca2+ signals.
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He L, Gao Y, Lin Y, Katsumi H, Fujita T, Yamamoto A. Improvement of pulmonary absorption of insulin and other water-soluble compounds by polyamines in rats. J Control Release 2007; 122:94-101. [PMID: 17651854 DOI: 10.1016/j.jconrel.2007.06.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Revised: 05/06/2007] [Accepted: 06/19/2007] [Indexed: 11/17/2022]
Abstract
The absorption enhancing effects of polyamines, spermine (SPM), spermidine (SPD) and putrescine (PUT) on the pulmonary absorption of poorly absorbable drugs were studied in rats. Insulin, 5(6)-carboxyfluorescein (CF), and fluorescein isothiocyanate-labeled dextrans (FDs) were chosen as models of poorly absorbable drugs. The absorption of insulin from the lung was enhanced in the presence of SPM and SPD, while PUT had almost no absorption enhancing effect for improving the pulmonary absorption of insulin in rats. SPM also improved the pulmonary absorption of FDs with various molecular weights, although we found almost no significant difference in the pulmonary absorption of CF with or without SPM. As for the pulmonary membrane toxicity of SPM, there was no significant difference in the release of protein and lactate dehydrogenase (LDH) with or without SPM in bronchoalveolar lavage fluid (BALF), indicating that SPM did not cause any membrane damage to the lung tissues. Furthermore, SPM did not affect the stability of insulin in BALF, suggesting that SPM might increase the permeability of insulin across the alveolar epithelium. In conclusion, polyamines, especially SPM can effectively improve the pulmonary absorption of insulin and other macromolecules without any membrane damage to the lung tissues.
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Affiliation(s)
- Lin He
- Department of Biopharmaceutics, Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto, Japan
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16
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Theodorou MC, Theodorou EC, Panagiotidis CA, Kyriakidis DA. Spermidine triggering effect to the signal transduction through the AtoS–AtoC/Az two-component system in Escherichia coli. Biochim Biophys Acta Gen Subj 2007; 1770:1104-14. [PMID: 17475408 DOI: 10.1016/j.bbagen.2007.03.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2006] [Revised: 03/06/2007] [Accepted: 03/16/2007] [Indexed: 11/16/2022]
Abstract
Recent analysis revealed that, in Escherichia coli the AtoS-AtoC/Az two-component system (TCS) and its target atoDAEB operon regulate the biosynthesis of short-chain poly-(R)-3-hydroxybutyrate (cPHB) biosynthesis, a biopolymer with many physiological roles, upon acetoacetate-mediated induction. We report here that spermidine further enhanced this effect, in E. coli that overproduces both components of the AtoS-AtoC/Az TCS, without altering their protein levels. However, bacteria that overproduce either AtoS or AtoC did not display this phenotype. The extrachromosomal introduction of AtoS-AtoC/Az in an E. coli DeltaatoSC strain restored cPHB biosynthesis to the level of the atoSC(+) cells, in the presence of the polyamine. Lack of enhanced cPHB production was observed in cells overproducing the TCS that did not have the atoDAEB operon. Spermidine attained the cPHB enhancement through the AtoC/Az response regulator phosphorylation, since atoC phosphorylation site mutants, which overproduce AtoS, accumulated less amounts of cPHB, compared to their wild-type counterparts. Exogenous addition of N(8)-acetyl-spermidine resulted in elevated amounts of cPHB but at lower levels than those attained upon spermidine addition. Furthermore, AtoS-AtoC/Az altered the intracellular distribution of cPHB according to the inducer recognized by the TCS. Overall, AtoS-AtoC/Az TCS was induced by spermidine to regulate both the biosynthesis and the intracellular distribution of cPHB in E. coli.
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Affiliation(s)
- Marina C Theodorou
- Laboratory of Biochemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, 54124, Greece
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17
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Pastorelli R, Carpi D, Campagna R, Airoldi L, Pohjanvirta R, Viluksela M, Hakansson H, Boutros PC, Moffat ID, Okey AB, Fanelli R. Differential Expression Profiling of the Hepatic Proteome in a Rat Model of Dioxin Resistance. Mol Cell Proteomics 2006; 5:882-94. [PMID: 16497791 DOI: 10.1074/mcp.m500415-mcp200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
One characteristic feature of acute 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) toxicity is dramatic interspecies and interstrain variability in sensitivity. This complicates dioxin risk assessment for humans. However, this variability also provides a means of characterizing mechanisms of dioxin toxicity. Long-Evans (Turku/AB) rats are orders of magnitude more susceptible to TCDD lethality than Han/Wistar (Kuopio) rats, and this difference constitutes a very useful model for identifying mechanisms of dioxin toxicity. We adopted a proteomic approach to identify the differential effects of TCDD exposure on liver protein expression in Han/Wistar rats as compared with Long-Evans rats. This allows determination of which, if any, protein markers are indicative of differences in dioxin susceptibility and/or responsible for conferring resistance. Differential protein expression in total liver protein was assessed using two-dimensional gel electrophoresis, computerized gel image analysis, in-gel digestion, and mass spectrometry. We observed significant changes in the abundance of several proteins, which fall into three general classes: (i) TCDD-independent and exclusively strain-specific (e.g. isoforms of the protein-disulfide isomerase A3, regucalcin, and agmatine ureohydrolase); (ii) strain-independent and only dependent on TCDD exposure (e.g. aldehyde dehydrogenase 3A1 and rat selenium-binding protein 2); (iii) dependent on both TCDD exposure and strain (e.g. oxidative stress-related proteins, apoptosis-inducing factor, and MAWD-binding protein). By integrating transcriptomic (microarray) data and genomic data (computational search of regulatory elements), we found that protein expression levels were mainly controlled at the level of transcription. These results reveal, for the first time, a subset of hepatic proteins that are differentially regulated in response to TCDD in a strain-specific manner. Some of these differential responses may play a role in establishing the major differences in TCDD response between these two strains of rats. As such, our work is expected to lead to new insights into the mechanism of TCDD toxicity and resistance.
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Affiliation(s)
- Roberta Pastorelli
- Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri, 20157 Milan, Italy.
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18
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García N, Zazueta C, Pavón N, Chávez E. Agaric acid induces mitochondrial permeability transition through its interaction with the adenine nucleotide translocase. Its dependence on membrane fluidity. Mitochondrion 2005; 5:272-81. [PMID: 16050990 DOI: 10.1016/j.mito.2005.05.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2005] [Revised: 05/17/2005] [Accepted: 05/31/2005] [Indexed: 11/26/2022]
Abstract
The effect of agaric acid as inducer of mitochondrial permeability transition was studied. It was found that: (i) agaric acid (AA) promoted efflux of accumulated Ca2+, collapse of transmembrane potential, and mitochondrial swelling; (ii) these effects depend on membrane fluidity; (iii) ADP inhibited the effect of AA on Ca2+ efflux, and (iv) AA blocked binding of the sulfhydryl reagent, eosin-5-maleimide, to the adenine nucleotide translocase. It is proposed that AA induces pore opening through binding of the citrate moiety to the ADP/ATP carrier; this interaction must be stabilized by insertion of the alkyl chain in the lipid milieu of the membrane.
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Affiliation(s)
- Noemí García
- Departamento de Bioquímica, Instituto Nacional de Cardiología, Ignacio Chávez, Juan Badiano No. 1, Col. Sección XVI, Tlalpan, DF 014080, Mexico
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19
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Salvi M, Toninello A. Effects of polyamines on mitochondrial Ca2+ transport. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2004; 1661:113-24. [PMID: 15003874 DOI: 10.1016/j.bbamem.2003.12.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2003] [Revised: 11/27/2003] [Accepted: 12/04/2003] [Indexed: 11/26/2022]
Abstract
Mammalian mitochondria are able to enhance Ca(2+) accumulation in the presence of polyamines by activating the saturable systems of Ca(2+) inward transport and buffering extramitochondrial Ca(2+) concentrations to levels similar to those in the cytosol of resting cells. This effect renders them responsive to regulate free Ca(2+) concentrations in the physioloical range. The mechanism involved is due to a rise in the affinity of the Ca(2+) transport system, induced by polyamines, most probably exhibiting allosteric behaviour. The regulatory site of this mechanism is the so-called S(1) binding site of polyamines, which operates in physiological conditions and is located in the energy well between the two peaks present in the energy profile of mitochondrial spermine transport. Spermine is bidirectionally transported across teh inner membrane by cycling, in which influx and efflux are driven by electrical and pH gradients, respectively. Most probably, polyamine affects the Ca(2+) transport system when it acts from the outside-that is, in the direction of its uniporter channel, in order to reach the S(1) site. Important physiological functions are related to activation of Ca(2+) transport systems by polyamines and their interactions with the S(1) site. These functions include a rise in the metabolic rate for energy supply and modulation of mitochondrial permeability transition induction, with consequent effects on the triggering of the apoptotic pathway.
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Affiliation(s)
- Mauro Salvi
- Dipartimento di Chimica Biologica, Universita' di Padova, Istituto di Neuroscienze del C.N.R., Unita' per lo Studio delle Biomembrane, Via G. Colombo 3, 35121 Padua, Italy
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20
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Abstract
Polyamines are polycations present in all living organisms and have been shown to play an important role in various physiological functions. Previous studies have shown that various amines including polyamines inhibit platelet activation. Among the amines tested tetra-amine, spermine is the potent inhibitor of platelet aggregation. In spite of vast literature on the anti-aggregatory effect of amines, there are no definitive studies testing their efficacy in an in vivo thrombosis model. In the present study, we investigated if polyamines could inhibit in-vivo thrombosis. A partially occlusive thrombus was generated by application of electric current in canine coronary artery. In control animals, the artery was completely in 76+/-14 min after the current was discontinued. When 40 mg/kg (1.44 mM) spermine was given immediately after stopping the current blood flow remained patent for >240 min. At equimolar concentration, triamine, spermidine and diamine putrescine are also equally effective in preventing thrombus development. The anti thrombic effect of polyamines was not associated with increased bleeding tendency, as judged by the amount of blood adsorbed by a gauge pad placed in a surgical incision extending to the muscle tissue and by a standard template bleeding. These results indicate that apart from inhibiting in-vitro platelet aggregation polyamines can also inhibit in-vivo thrombus formation.
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Affiliation(s)
- Rajbabu Pakala
- Department of Internal Medicine, Division of Cardiology, University of Texas Health Science Center-Medical School, Houston, TX 77030, USA.
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21
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Kito Y, Suzuki H. Pacemaker frequency is increased by sodium nitroprusside in the guinea pig gastric antrum. J Physiol 2003; 546:191-205. [PMID: 12509488 PMCID: PMC2342478 DOI: 10.1113/jphysiol.2002.027607] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
In the guinea pig gastric antrum, the effects of sodium nitroprusside (SNP), an NO donor, on pacemaker potentials were investigated in the presence of nifedipine. The pacemaker potentials consisted of primary and plateau components; SNP (> 1 microM) increased the frequency of occurrence of these pacemaker potentials, while inhibiting the plateau component. 1H-[1,2,4]-Oxadiazole [4,3-a] quinoxalin-1-one, an inhibitor of guanylate cyclase, had no effect on the excitatory actions of SNP on the frequency of pacemaker potentials. Other types of NO donor, (+/-)-S-nitroso-N-acetylpenicillamine, 3-morpholino-sydnonimine and 8-bromoguanosine 3'5'-cyclic monophosphate had no excitatory effect on pacemaker activity. Forskolin, an activator of adenylate cyclase, or 4,4'-diisothiocyano-stilbene-2,2'-disulphonic acid, an inhibitor of the Ca(2+)-activated Cl(-) channel, strongly attenuated the generation of pacemaker potentials, and SNP added in the presence of these chemicals restored the generation of pacemaker potentials. The pacemaker potentials evoked by SNP were abolished in low-Ca(2+) solution or by membrane depolarization with high-K(+) solution. The SNP-induced generation of pacemaker potentials was not prevented by cyclopiazonic acid, an inhibitor of internal Ca(2+)-ATPase, but was limited to a transient burst by iodoacetic acid, an inhibitor of glycolysis, carbonyl cyanide m-chlorophenyl-hydrazone, a mitochondrial protonophore, or 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester, an intracellular Ca(2+) chelator. These results suggest that the SNP-induced increase in the frequency of pacemaker potentials is related to the elevated intracellular Ca(2+) concentrations due to release from mitochondria, and these actions may be independent of the activation of guanylate cyclase.
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Affiliation(s)
- Yoshihiko Kito
- Department of Physiology, Nagoya City University Medical School, Mizuho-ku, Nagoya 467-8601, Japan.
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22
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Teti D, Visalli M, McNair H. Analysis of polyamines as markers of (patho)physiological conditions. J Chromatogr B Analyt Technol Biomed Life Sci 2002; 781:107-49. [PMID: 12450656 DOI: 10.1016/s1570-0232(02)00669-4] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The aliphatic polyamines, putrescine, spermidine and spermine, are normal cell constituents that play important roles in cell proliferation and differentiation. The equilibrium between cellular uptake and release and the balanced activities of biosynthetic and catabolic enzymes of polyamines are essential for normal homeostasis in the proliferation and functions of cells and tissues. However, the intracellular polyamine content increases in hyperplastic or neoplastic growth. Although the involvement of polyamines in physiological and pathological cell proliferation and differentiation has been well established, the role they play is quite different in relation to cell systems and animal models and is dependent on inducer agents and stimuli. Also, the experimental procedures used to deplete polyamines have been shown to influence the cell responses. In this paper, the assay methods currently in use for polyamines are reviewed and compared with respect to sensitivity, reproducibility and applicability to routine analysis. The relevance of polyamine metabolism and the uptake/release process in many physiological and pathological processes is highlighted, and the cellular polyamine pathways are discussed in relation to the possible diagnostic and therapeutic significance of these mediators.
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Affiliation(s)
- Diana Teti
- Department of Experimental Pathology and Microbiology, Section of Experimental Pathology, Azienda Policlinico Universitario, Torre Biologica, IV piano, Via Consolare Valeria, 98125 Messina, Italy.
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23
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Montero M, Lobaton CD, Moreno A, Alvarez J. A novel regulatory mechanism of the mitochondrial Ca2+ uniporter revealed by the p38 mitogen-activated protein kinase inhibitor SB202190. FASEB J 2002; 16:1955-7. [PMID: 12368236 DOI: 10.1096/fj.02-0553fje] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
It is widely acknowledged that mitochondrial Ca2+ uptake modulates the cytosolic [Ca2+] ([Ca2+]c) acting as a transient Ca2+ buffer. In addition, mitochondrial [Ca2+] ([Ca2+]M) regulates the rate of respiration and may trigger opening of the permeability transition pore and start apoptosis. However, no mechanism for the physiological regulation of mitochondrial Ca2+ uptake has been described. We show here that SB202190, an inhibitor of p38 mitogen-activated protein (MAP) kinase, strongly stimulates ruthenium red-sensitive mitochondrial Ca2+ uptake, both in intact and in permeabilized HeLa cells. The [Ca2+]M peak induced by agonists was increased about fourfold in the presence of the inhibitor, with a concomitant reduction in the [Ca2+]c peak. The stimulation occurred fast and was rapidly reversible. In addition, experiments in permeabilized cells perfused with controlled [Ca2+] showed that SB202190 stimulated mitochondrial Ca2+ uptake by more than 10-fold, but only in the physiological [Ca2+]c range (1-4 mM). Other structurally related p38 MAP kinase inhibitors (SB203580, PD169316, or SB220025) produced little or no effect. Our data suggest that in HeLa cells, a protein kinase sensitive to SB202190 tonically inhibits the mitochondrial Ca2+ uniporter. This novel regulatory mechanism may be of paramount importance to modulate mitochondrial Ca2+ uptake under different physiopathological conditions.
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Affiliation(s)
- Mayte Montero
- Instituto de Biología y Genética Molecular, Departamento de Bioquímica y Biología Molecular y Fisiología, Facultad de Medicina, Universidad de Valladolid and Consejo Superior de Investigaciones Científicas, Ramón y Cajal, 7, E-47005 Valladolid, Spain
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24
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Nilsson BO, Gomez MF, Swärd K, Hellstrand P. Regulation of Ca2+ channel and phosphatase activities by polyamines in intestinal and vascular smooth muscle--implications for cellular growth and contractility. ACTA PHYSIOLOGICA SCANDINAVICA 2002; 176:33-41. [PMID: 12193217 DOI: 10.1046/j.1365-201x.2002.01013.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Polyamines added extracellularly to intestinal and vascular smooth muscle cells cause relaxation through inhibition of Ca2+ channel activity. Intracellularly applied polyamines also affect Ca2+ channel properties. Polyamines do not readily pass over the plasma membrane because of their positive charges but in permeabilized smooth muscle preparations they have free access to the cytoplasm. In this system they increase sensitivity of the contractile machinery to Ca2+ through inhibition of myosin phosphatase activity. The magnitude of Ca2+ channel and phosphatase inhibition depends on the number of positive charges on the polyamine molecule. Polyamines have an obligatory, but yet undefined, role in regulation of cell growth and proliferation. Several groups of protein kinases, such as tyrosine and mitogen activated protein (MAP)-kinases transmit the growth signal from the plasma membrane to the cell nucleus where mitosis and protein synthesis are initiated. The data reviewed here show that polyamines may affect such signal transmission via inhibition of phosphatase activity.
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Affiliation(s)
- B-O Nilsson
- Department of Physiological Sciences, Lund University, Lund, Sweden.
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25
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Pakala R. Effect of polyamines on in vitro platelet aggregation and in vivo thrombus formation. CARDIOVASCULAR RADIATION MEDICINE 2002; 3:213-20. [PMID: 12974377 DOI: 10.1016/s1522-1865(03)00097-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
INTRODUCTION Polyamines are polycations present in all living organisms and have been shown to play an important role in various physiological functions. Previous studies have shown that various amines including polyamines inhibited platelet activation, but there were no definitive studies testing their efficacy in an in vivo thrombosis model. We carried out detailed in vitro platelet aggregation studies using various concentrations of polyamines as well as agonists. METHODS Platelet aggregation was measured by a turbidimetric method. Electric current induced in vivo thrombosis model is used for assessing antithrombotic effect. Incidence of bleeding was evaluated by template bleeding and incisional bleeding. RESULTS Polyamines inhibited agonist-induced platelet aggregation in a dose-dependent manner. The inhibitory effect of polyamines is inversely proportional to the concentration of the agonist used. Among the polyamines, spermine is the potent inhibitor of platelet aggregation. A partially occlusive thrombus was generated by application of electric current in canine coronary artery. In control animals, the artery was completely occluded in 70 +/- 11 min after the current was discontinued. Blood flow remained patent for >240 min when 2 mg/kg spermine was given immediately after stopping the current. The antithrombotic effect of spermine was not associated with increased bleeding tendency. CONCLUSION These results indicate that apart from inhibiting in vitro platelet aggregation polyamines can also inhibit in vivo thrombus formation. To our knowledge, this is the first study demonstrating this phenomenon.
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Affiliation(s)
- Rajbabu Pakala
- Division of Cardiology, Department of Internal Medicine, University of Texas Health Science Center-Medical School, Houston, TX 77030, USA.
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26
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Curtis MJ, Wolpert TJ. The oat mitochondrial permeability transition and its implication in victorin binding and induced cell death. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2002; 29:295-312. [PMID: 11844107 DOI: 10.1046/j.0960-7412.2001.01213.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The mitochondrion has emerged as a key regulator of apoptosis, a form of animal programmed cell death (PCD). The mitochondrial permeability transition (MPT), facilitated by a pore-mediated, rapid permeability increase in the inner membrane, has been implicated as an early and critical step of apoptosis. Victorin, the host-selective toxin produced by Cochliobolus victoriae, the causal agent of victoria blight of oats, has been demonstrated to bind to the mitochondrial P-protein and also induces a form of PCD. Previous results suggest that a MPT may facilitate victorin's access to the mitochondrial matrix and binding to the P-protein: (i) victorin-induced cell death displays features similar to apoptosis; (ii) in vivo, victorin binds to the mitochondrial P-protein only in toxin-sensitive genotypes whereas victorin binds equally well to P-protein isolated from toxin-sensitive and insensitive oats; (iii) isolated, untreated mitochondria are impermeable to victorin. The data implicate an in vivo change in mitochondrial permeability in response to victorin. This study focused on whether oat mitochondria can undergo a MPT. Isolated oat mitochondria demonstrated high-amplitude swelling when treated with spermine or Ca2+ in the presence of the Ca2+-ionophore A23187, and when treated with mastoparan, an inducer of the MPT in rat liver mitochondria. In all cases, swelling demonstrated size exclusion in the range 0.9-1.7 kDa, similar to that found in animal mitochondria. Further, MPT-inducing conditions permitted victorin access to the mitochondrial matrix and binding to the P-protein. In vivo, victorin treatment induced the collapse of mitochondrial transmembrane potential within 2 h, indicating a MPT. Also, the victorin-induced collapse of membrane potential was clearly distinct from that induced by uncoupling respiration, as the latter event prevented the victorin-induced PCD response and binding to P-protein. These results demonstrate that a MPT can occur in oat mitochondria in vitro, and are consistent with the hypothesis that an MPT, which allows victorin access to the mitochondrial matrix and binding to the P-protein, occurs in vivo during victorin-induced PCD.
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Affiliation(s)
- Marc J Curtis
- Molecular Cellular Biology Program, and Center for Gene Research and Biotechnology, Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331-2902, USA
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27
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Palmi M, Youmbi GT, Sgaragli G, Meini A, Benocci A, Fusi F, Frosini M, Della Corte L, Davey G, Tipton KF. The mitochondrial permeability transition and taurine. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2002; 483:87-96. [PMID: 11787652 DOI: 10.1007/0-306-46838-7_8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Perturbed cellular calcium homeostasis has been implicated in both apoptosis and necrosis, but the role of altered mitochondrial calcium handling in the cell death process is unclear. Recently we found that taurine, a naturally occurring amino acid potentiates Ca2+ sequestration by rat liver mitochondria. These data, which accounted for the taurine antagonism on Ca2+ release induced by the neurotoxins 1-methyl-4-phenylpyridinium plus 6-hydroxy dopamine previously reported, prompted us to investigate the effects of taurine on the permeability transition (PT) induced experimentally by high Ca2+ plus phosphate concentrations. The parameters used to measure the PT were, mitochondrial swelling, cytochrome c release and membrane potential changes. The results showed that, whereas taurine failed to reverse changes of these parameters, cyclosporin A completely reversed them. Even though these results exclude a role in PT regulation under such gross insult conditions, they cannot exclude an important role for taurine in controlling pore-opening under milder more physiological PT-inducing conditions.
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Affiliation(s)
- M Palmi
- Istituto di Scienze Farmacologiche, Università di Siena, Italy
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28
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Liu W, Liu R, Schreiber SS, Baudry M. Role of polyamine metabolism in kainic acid excitotoxicity in organotypic hippocampal slice cultures. J Neurochem 2001; 79:976-84. [PMID: 11739609 DOI: 10.1046/j.1471-4159.2001.00650.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Polyamines are ubiquitous cations that are essential for cell growth, regeneration and differentiation. Increases in polyamine metabolism have been implicated in several neuropathological conditions, including excitotoxicity. However, the precise role of polyamines in neuronal degeneration is still unclear. To investigate mechanisms by which polyamines could contribute to excitotoxic neuronal death, the present study examined the role of the polyamine interconversion pathway in kainic acid (KA) neurotoxicity using organotypic hippocampal slice cultures. Treatment of cultures with N1,N(2)-bis(2,3-butadienyl)-1,4-butanediamine (MDL 72527), an irreversible inhibitor of polyamine oxidase, resulted in a partial but significant neuronal protection, especially in CA1 region. In addition, this pre-treatment also attenuated KA-induced increase in levels of lipid peroxidation, cytosolic cytochrome C release and glial cell activation. Furthermore, pre-treatment with a combination of cyclosporin A (an inhibitor of the mitochondrial permeability transition pore) and MDL 72527 resulted in an additive and almost total neuronal protection against KA toxicity, while the combination of MDL 72527 and EUK-134 (a synthetic catalase/superoxide dismutase mimetic) did not provide additive protection. These data strongly suggest that the polyamine interconversion pathway partially contributes to KA-induced neurodegeneration via the production of reactive oxygen species.
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Affiliation(s)
- W Liu
- Neuroscience Program, School of Medicine, University of Southern California, Los Angeles, California 90089-2520, USA
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29
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Mather M, Rottenberg H. Polycations induce the release of soluble intermembrane mitochondrial proteins. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1503:357-68. [PMID: 11115647 DOI: 10.1016/s0005-2728(00)00231-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The release of proapoptotic proteins from the intermembrane space of mitochondria is an early critical step in many pathways to apoptosis. Induction of the mitochondrial permeability transition pore (PTP) was suggested to be the mechanism of the release of soluble mitochondrial intermembrane proteins (SIMP) in apoptosis. However, several studies suggested that proapoptotic proteins (e.g. Bax and Bid) can induce the release of SIMP (e.g. cytochrome c (cyt c) and adenylate kinase 2 (AK2)) in vivo and in vitro independent of PTP. We have found that a number of structurally diverse polycations, such as aliphatic polyamines (e.g. spermine and to a lesser extent spermidine), aminoglycosides (e.g. streptomycin, gentamicin and neomycin), and cytotoxic peptides (e.g. melittin), induce the release of SIMP from liver mitochondria, in vitro. All the polycations released AK2 together with cyt c, suggesting that rupture of the outer membrane is a common mechanism of cyt c release by these polycations. Several polycations (e.g. spermine, spermidine and neomycin) induced SIMP release without inducing significant swelling, and this release was not inhibited significantly by the PTP inhibitor cyclosporin. In contrast, under the same conditions, streptomycin and melittin induced swelling and SIMP release that was inhibited strongly by cyclosporin. Gentamicin-induced swelling and release of SIMP were partially inhibited by cyclosporin. The affinity of polyamines to the anionic phospholipids of the mitochondrial membranes (spermine=neomycin>gentamicin>streptomycin=spermidine) correlated roughly with their ability to induce PTP-independent release of SIMP, which suggests that the binding of polycations to the anionic phospholipids of the outer mitochondrial membrane facilitates the rupture of this membrane. However, some polycations facilitated the induction of PTP, possibly by binding to cardiolipin on the inner membrane. This dual mechanism may be relevant to the induction of SIMP release in apoptosis.
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Affiliation(s)
- M Mather
- MCP Hahnemann University, M.S. 435, 245 N. 15th Street, Philadelphia, PA 19102, USA
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Gunter TE, Buntinas L, Sparagna G, Eliseev R, Gunter K. Mitochondrial calcium transport: mechanisms and functions. Cell Calcium 2000; 28:285-96. [PMID: 11115368 DOI: 10.1054/ceca.2000.0168] [Citation(s) in RCA: 279] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Ca(2+)transport across the mitochondrial inner membrane is facilitated by transporters having four distinct sets of characteristics as well as through the Ca(2+)-induced mitochondrial permeability transition pore (PTP). There are two modes of inward transport, referred to as the Ca(2+)uniporter and the rapid mode or RaM. There are also two distinct mechanisms mediating outward transport, which are not associated with the PTP, referred to as the Na(+)-dependent and the Na(+)-independent Ca(2+)efflux mechanisms. Several important functions have been proposed for these mechanisms, including control of the metabolic rate for cellular energy (ATP) production, modulation of the amplitude and shape of cytosolic Ca(2+)transients, and induction of apoptosis through release of cytochrome c from the mitochondrial inter membrane space into the cytosolic space. The goals of this review are to survey the literature describing the characteristics of the mechanisms of mitochondrial Ca(2+)transport and their proposed physiological functions, emphasizing the more recent contributions, and to consider how the observed characteristics of the mitochondrial Ca(2+)transport mechanisms affect our understanding of their functions.
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Affiliation(s)
- T E Gunter
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA.
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Chávez E, Peña A, Zazueta C, Ramírez J, García N, Carrillo R. Inactivation of mitochondrial permeability transition pore by octylguanidine and octylamine. J Bioenerg Biomembr 2000; 32:193-8. [PMID: 11768752 DOI: 10.1023/a:1005516115189] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Mitochondrial permeability transition occurs through a Ca2+-dependent opening of a transmembrane pore, whose identity has been attributed to that of the adenine nucleotide translocase (ANT). In this work, we induced permeability transition by adding 0.5 microM carboxyatractyloside. The process was evaluated analyzing Ca2+ efflux, a drop in transmembrane electric gradient, and swelling. We found that the amphiphyllic cations octylguanidine and octylamine, at the concentration of 100 microM, inhibited, almost completely, nonspecific membrane permeability. Hexylguanidine, hexylamine, as well as guanidine chloride and hydroxylamine failed to do so. The inhibition was reversed after the addition of 40 mM Li+, Na+ K+, Rb+, or Cs+; K+ was the most effective. We propose that the positive charge of the amines interact with negative charges of membrane proteins, more likely the ADP/ATP carrier, while the alkyl chain penetrates into the hydrophobic milieu of the inner membrane, fixing the reagent.
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Affiliation(s)
- E Chávez
- Departamento de Bioquímica Instituto Nacional de Cardiología, Ignacio Chávez, UNAM, Mexico, DF, Mexico.
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Palmi M, Youmbi GT, Fusi F, Sgaragli GP, Dixon HB, Frosini M, Tipton KF. Potentiation of mitochondrial Ca2+ sequestration by taurine. Biochem Pharmacol 1999; 58:1123-31. [PMID: 10484070 DOI: 10.1016/s0006-2952(99)00183-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The effects of taurine (2-aminoethanesulphonic acid) and its analogues, 2-aminoethylarsonic acid, 2-hydroxyethanesulphonic (isethionic) acid, 3-aminopropanesulphonic acid, 2-aminoethylphosphonic acid, and N,N-dimethyltaurine, were studied on the transport of Ca2+ by mitochondria isolated from rat liver. Taurine enhanced Ca2+ uptake in an apparently saturable process, with a Km value of about 2.63 mM. Taurine behaved as an uncompetitive activator of Ca2+ uptake, increasing both the apparent Km and Vmax values of the process. This effect was not modified in the presence of cyclosporin A (CsA). N,N-Dimethyltaurine also stimulated Ca2+ uptake at higher concentrations, but there was no evidence that the process was saturable over the concentration range used (1-10 mM). Aminoethylarsonate was a weak inhibitor of basal Ca2+ uptake, but inhibited that stimulated by taurine in an apparently competitive fashion (Ki = 0.05 mM). The other analogues had no significant effects on this process. Taurine either in the presence or the absence of CsA had no effect on Ca2+ release induced by 200 nM ruthenium red. Thus, the mechanism of taurine-enhanced Ca2+ accumulation appears to involve stimulation of Ca2+ uptake via the uniport system rather than inhibition of Ca2+ release via the ion (Na+/Ca2+ and/or H+/Ca2+) exchangers or by taurine modulating the permeability transition of the mitochondrial inner membrane. Overall, these findings indicate an interaction of taurine with an as yet unidentified mitochondrial site which might regulate the activity of the uniporter. The unique role of taurine in modulating mitochondrial Ca2+ homeostasis might be of particular importance under pathological conditions that are characterised by cell Ca2+ overload, such as ischaemia and oxidative stress.
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Affiliation(s)
- M Palmi
- Istituto di Scienze Farmacologiche, Universitá di Siena, Italy.
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Rustenbeck I, Löptien D, Fricke K, Lenzen S, Reiter H. Polyamine modulation of mitochondrial calcium transport. II. Inhibition of mitochondrial permeability transition by aliphatic polyamines but not by aminoglucosides. Biochem Pharmacol 1998; 56:987-95. [PMID: 9776309 DOI: 10.1016/s0006-2952(98)00233-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In this study, the effects of polyamines and analogous compounds on mitochondrial permeability transition were characterized to distinguish between these effects and those on mitochondrial Ca2+ uptake, which are described in an accompanying report (Rustenbeck et al., Biochem Pharmacol 8: 977-985, 1998). When a transitional Ca2+ release from Ca2+-loaded mitochondria was induced by an acute increase in Ca2+ concentration in a cytosol-adapted incubation medium (Ca2+ pulse), this process was inhibited, but not abolished by spermine in the concentration range of 0.4 to 20 mM. The aminoglucoside, gentamicin, and the basic polypeptide, poly-L-lysine, which like spermine are able to enhance mitochondrial Ca2+ accumulation (preceding paper), had no or only a minimal inhibitory effect, while the aliphatic polyamine, bis(hexamethylene)triamine, which is unable to enhance mitochondrial Ca2+ accumulation, achieved a complete inhibition at 4 mM. The conclusion that the Ca2+ efflux was due to opening of the permeability transition pore was supported by measurements of mitochondrial membrane potential, ATP production, and oxygen consumption. Mg2+, a known inhibitor of mitochondrial membrane permeability transition, did not mimic the effects of spermine on mitochondrial Ca2+ accumulation, while ADP, the main endogenous inhibitor, showed both effects. However, a combination of spermine and ADP was significantly more effective than ADP alone in restoring low Ca2+ concentrations after a Ca2+ pulse. Two different groups of spermine binding sites were found at intact liver mitochondria, characterized by dissociation constants of 0.5 or 4.7 mM and maximal binding capacities of 4.6 or 19.7 nmol/mg of protein, respectively. In contrast to aminoglucosides, the aliphatic polyamine bis(hexamethylene)triamine did not displace spermine from mitochondrial binding sites. The total intracellular concentration of spermine in hepatocytes was measured to be ca. 450 microM and the free cytoplasmic concentration was estimated to be in the range of 10-100 microM. In conclusion, the enhancement of mitochondrial Ca2+ uptake by spermine is not an epiphenomenon of the inhibition of permeability transition. The physiological role of spermine appears to be that of an enhancer of mitochondrial Ca2+ accumulation rather than an inhibitor of permeability transition.
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Affiliation(s)
- I Rustenbeck
- Institute of Pharmacology and Toxicology, University of Göttingen, Germany
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