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Nowak G, Bakajsova D. Protein kinase C-α activation promotes recovery of mitochondrial function and cell survival following oxidant injury in renal cells. Am J Physiol Renal Physiol 2012; 303:F515-26. [PMID: 22674023 DOI: 10.1152/ajprenal.00072.2012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
We demonstrated that nonselective PKC activation promotes mitochondrial function in renal proximal tubular cells (RPTC) following toxicant injury. However, the specific PKC isozyme mediating this effect is unknown. This study investigated the role of PKC-α in the recovery of mitochondrial functions in oxidant-injured RPTC. Wild-type PKC-α (wtPKC-α) and inactive PKC-α mutants were overexpressed in RPTC to selectively increase or block PKC-α activation. Oxidant (tert-butyl hydroperoxidel; TBHP) exposure activated PKC-α in RPTC but decreased PKC-α levels in mitochondria following treatment. Uncoupled and state 3 respirations and activities of complexes I and IV in TBHP-injured cells decreased to 55, 44, 49, and 65% of controls, respectively. F(0)F(1)-ATPase activity and ATP content in injured RPTC decreased to 59 and 60% of controls, respectively. Oxidant exposure increased reactive oxygen species (ROS) production by 210% and induced mitochondrial fragmentation and 52% RPTC lysis. Overexpressing wtPKC-α did not block TBHP-induced ROS production but improved respiration and complex I activity, restored complex IV and F(0)F(1)-ATPase activities, promoted recovery of ATP content, blocked mitochondrial fragmentation, and reduced RPTC lysis to 14%. In contrast, inhibiting PKC-α 1) induced mitochondrial hyperpolarization and fragmentation; 2) blocked increases in ROS production; 3) prevented recovery of respiratory complexes and F(0)F(1)-ATPase activities, respiration, and ATP content; and 4) exacerbated TBHP-induced RPTC lysis. We conclude that 1) activation of PKC-α prevents mitochondrial hyperpolarization and fragmentation, decreases cell death, and promotes recovery of mitochondrial respiration and ATP content following oxidant injury in RPTC; and 2) respiratory complexes I and IV and F(0)F(1)-ATPase are targets of active PKC-α.
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Affiliation(s)
- Grazyna Nowak
- Univ. of Arkansas for Medical Sciences, Dept. of Pharmaceutical Sciences, 4301 West Markham St., Little Rock, AR 72205, USA.
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Antico Arciuch VG, Elguero ME, Poderoso JJ, Carreras MC. Mitochondrial regulation of cell cycle and proliferation. Antioxid Redox Signal 2012; 16:1150-80. [PMID: 21967640 PMCID: PMC3315176 DOI: 10.1089/ars.2011.4085] [Citation(s) in RCA: 294] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 10/03/2011] [Accepted: 10/03/2011] [Indexed: 01/01/2023]
Abstract
Eukaryotic mitochondria resulted from symbiotic incorporation of α-proteobacteria into ancient archaea species. During evolution, mitochondria lost most of the prokaryotic bacterial genes and only conserved a small fraction including those encoding 13 proteins of the respiratory chain. In this process, many functions were transferred to the host cells, but mitochondria gained a central role in the regulation of cell proliferation and apoptosis, and in the modulation of metabolism; accordingly, defective organelles contribute to cell transformation and cancer, diabetes, and neurodegenerative diseases. Most cell and transcriptional effects of mitochondria depend on the modulation of respiratory rate and on the production of hydrogen peroxide released into the cytosol. The mitochondrial oxidative rate has to remain depressed for cell proliferation; even in the presence of O₂, energy is preferentially obtained from increased glycolysis (Warburg effect). In response to stress signals, traffic of pro- and antiapoptotic mitochondrial proteins in the intermembrane space (B-cell lymphoma-extra large, Bcl-2-associated death promoter, Bcl-2 associated X-protein and cytochrome c) is modulated by the redox condition determined by mitochondrial O₂ utilization and mitochondrial nitric oxide metabolism. In this article, we highlight the traffic of the different canonical signaling pathways to mitochondria and the contributions of organelles to redox regulation of kinases. Finally, we analyze the dynamics of the mitochondrial population in cell cycle and apoptosis.
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Affiliation(s)
| | - María Eugenia Elguero
- Laboratory of Oxygen Metabolism, University of Buenos Aires, University Hospital, Buenos Aires, Argentina
| | - Juan José Poderoso
- Laboratory of Oxygen Metabolism, University of Buenos Aires, University Hospital, Buenos Aires, Argentina
- Department of Internal Medicine, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina
- CONICET, Buenos Aires, Argentina
| | - María Cecilia Carreras
- Laboratory of Oxygen Metabolism, University of Buenos Aires, University Hospital, Buenos Aires, Argentina
- CONICET, Buenos Aires, Argentina
- Department of Clinical Biochemistry, INFIBIOC and School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
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Bononi A, Agnoletto C, De Marchi E, Marchi S, Patergnani S, Bonora M, Giorgi C, Missiroli S, Poletti F, Rimessi A, Pinton P. Protein kinases and phosphatases in the control of cell fate. Enzyme Res 2011; 2011:329098. [PMID: 21904669 PMCID: PMC3166778 DOI: 10.4061/2011/329098] [Citation(s) in RCA: 209] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 05/06/2011] [Accepted: 06/08/2011] [Indexed: 12/19/2022] Open
Abstract
Protein phosphorylation controls many aspects of cell fate and is often deregulated in pathological conditions. Several recent findings have provided an intriguing insight into the spatial regulation of protein phosphorylation across different subcellular compartments and how this can be finely orchestrated by specific kinases and phosphatases. In this review, the focus will be placed on (i) the phosphoinositide 3-kinase (PI3K) pathway, specifically on the kinases Akt and mTOR and on the phosphatases PP2a and PTEN, and on (ii) the PKC family of serine/threonine kinases. We will look at general aspects of cell physiology controlled by these kinases and phosphatases, highlighting the signalling pathways that drive cell division, proliferation, and apoptosis.
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Affiliation(s)
- Angela Bononi
- Section of General Pathology, Department of Experimental and Diagnostic Medicine, Interdisciplinary Center for the Study of Inflammation (ICSI) and LTTA Center, University of Ferrara, 44100 Ferrara, Italy
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Sakaino M, Ishigaki M, Ohgari Y, Kitajima S, Masaki R, Yamamoto A, Taketani S. Dual mitochondrial localization and different roles of the reversible reaction of mammalian ferrochelatase. FEBS J 2009; 276:5559-70. [PMID: 19691493 DOI: 10.1111/j.1742-4658.2009.07248.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Ferrochelatase catalyzes the insertion of ferrous ions into protoporphyrin IX to produce heme. Previously, it was found that this enzyme also participates in the reverse reaction of iron removal from heme. To clarify the role of the reverse reaction of ferrochelatase in cells, mouse liver mitochondria were fractionated to examine the localization of ferrochelatase, and it was found that the enzyme localizes not only to the inner membrane, but also to the outer membrane. Observations by immunoelectron microscopy confirmed the dual localization of ferrochelatase in ferrochelatase-expressing human embryonic kidney cells and mouse liver mitochondria. The conventional (zinc-insertion) activities of the enzyme in the inner and outer membranes were similar, whereas the iron-removal activity was high in the outer membrane. 2D gel analysis revealed that two types of the enzyme with different isoelectric points were present in mitochondria, and the acidic form, which was enriched in the outer membrane, was found to be phosphorylated. Mutation of human ferrochelatase showed that serine residues at positions 130 and 303 were phosphorylated, and serine at position 130 may be involved in the balance of the reversible catalytic reaction. When mouse erythroleukemia cells were treated with 12-O-tetradecanoyl-phorbol 13-acetate, an activator of protein kinase C, or hemin, phospho-ferrochelatase levels increased, with a concomitant decrease in zinc-insertion activity and a slight increase in iron-removal activity. These results suggest that ferrochelatase localizes to both the mitochondrial outer and inner membranes and that the change in the equilibrium position of the forward and reverse activities may be regulated by the phosphorylation of ferrochelatase.
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Traore K, Sharma R, Thimmulappa RK, Watson WH, Biswal S, Trush MA. Redox-regulation of Erk1/2-directed phosphatase by reactive oxygen species: role in signaling TPA-induced growth arrest in ML-1 cells. J Cell Physiol 2008; 216:276-85. [PMID: 18270969 DOI: 10.1002/jcp.21403] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Extracellular signal-regulated kinase (Erk)1/2 activity signals myeloid cell differentiation induced by 12-O-tetradecanoyl-phorbol-13-acetate (TPA). Previously, we reported that Erk1/2 activation (phosphorylation) induced by TPA required reactive oxygen species (ROS) as a second messenger. Here, we hypothesized that ROS generated in response to TPA inhibit Erk1/2-directed phosphatase activity, which leads to an increase phosphorylation of Erk1/2 to signal p21(WAF1/Cip1)-mediated growth arrest in ML-1 cells. Incubation of ML-1 cells with TPA resulted in a marked accumulation of phosphorylated Erk1/2, and is subsequent to H2O2 generation. Interestingly, post-TPA-treatment with N-acetylcysteine (NAC) stimulated a marked and a rapid dephosphorylation of Erk1/2, suggesting a regeneration of Erk1/2-directed phospahatase activity by NAC. ROS generation in ML-1 cells induced by TPA was suggested to occur in the mitochondrial electron transport chain (METC) based on the following observations: (i) undifferentiated ML-1 cells not only lack p67-phox and but also express a low level of p47-phox key components required for NADPH oxidase enzymatic activity, (ii) pretreatment with DPI, an inhibitor of NADH- and NADPH-dependent enzymes, or rhein, an inhibitor of complex I, blocked the ROS generation, and (iii) examination of the microarray analysis data and Western blot analysis data revealed an induction of MnSOD expression at both mRNA and protein levels in response to TPA. MnSOD is a key member of the mitochondrial defense system against mitochondrial-derived superoxide. Together, this study suggested that TPA stimulated ROS generation as a second messenger to activate Erk1/2 via a redox-mediated inhibition of Erk1/2-directed phosphatase in ML-1 cells.
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Affiliation(s)
- Kassim Traore
- Department of Environmental Health Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland 21205, USA.
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Colome J, Ruiz-Moreno JM, Montero JA, Fernandez E. Diode laser-induced mitosis in the rabbit retinal pigment epithelium. Ophthalmic Surg Lasers Imaging Retina 2007; 38:484-90. [PMID: 18050811 DOI: 10.3928/15428877-20071101-07] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVE The induction of retinal pigment epithelium (RPE) proliferation without damaging the inner layers of the retina might be helpful in patients with RPE atrophic changes and degeneration. This study aimed to induce mitosis in the RPE of the rabbit after subthreshold photocoagulation with the diode laser. MATERIALS AND METHODS Twenty-five male Dutch rabbits received retinal photocoagulation using an 810-nm diode laser with different power settings and exposure times. The eyes were processed for light microscopy, electron transmission microscopy, and immunohistochemistry. RESULTS Neither morphological alterations nor mitotic activity was found after 5-mJ energies. Retinal layers were not affected and RPE hyperplasia appeared in the treated areas associated with mitotic activity when 10 mJ was used. Mitosis induction and retinal damage appeared with 20, 50, and 100 mJ and were associated with ophthalmoscopic damage. CONCLUSIONS The use of subthreshold 810-nm diode laser treatment may induce mitosis in the RPE without causing damage to the neighboring layers.
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Affiliation(s)
- Jorge Colome
- Department of Ophthalmology, Miguel Hernández University School of Medicine, Alicante, Spain
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Wang Y, Biswas G, Prabu SK, Avadhani NG. Modulation of mitochondrial metabolic function by phorbol 12-myristate 13-acetate through increased mitochondrial translocation of protein kinase Calpha in C2C12 myocytes. Biochem Pharmacol 2006; 72:881-92. [PMID: 16899228 DOI: 10.1016/j.bcp.2006.06.032] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2006] [Revised: 06/20/2006] [Accepted: 06/20/2006] [Indexed: 12/30/2022]
Abstract
Protein kinase C (PKC) agonists including phorbol 12-myristate 13-acetate (PMA) not only induce the redistribution of cytosolic PKC to various subcellular compartments but also activate the kinase domain of the protein. In the present study we have investigated the nature of mitochondrial PKC pool and its effects on mitochondrial function in cells treated with PMA. Treatment of C2C12 myoblasts, C6 glioma and COS7 cells with PMA resulted in a dramatic redistribution of intracellular PKCalpha pool, with large fraction of the protein pool sequestered in the mitochondrial compartment. We also observed mitochondrial PKCdelta accumulation in a cell restricted manner. The intramitochondrial localization was ascertained by using a combination of protection against protease treatment of isolated mitochondria and immunofluorescence microscopy. PMA-induced mitochondrial localization of PKCalpha was accompanied by increased mitochondrial PKC activity, altered cell morphology, disruption of mitochondrial membrane potential, decreased complex I and pyruvate dehydrogenase activities, and increased mitochondrial ROS production. All of these changes could be retarded by treatment with PKC inhibitors. These results show a direct role for PMA-mediated PKCalpha translocation to mitochondria in inducing mitochondrial toxicity.
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Affiliation(s)
- Ying Wang
- Laboratories of Biochemistry, Department of Animal Biology and The Mari Lowe Center for Comparative Oncology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Horbinski C, Chu CT. Kinase signaling cascades in the mitochondrion: a matter of life or death. Free Radic Biol Med 2005; 38:2-11. [PMID: 15589366 DOI: 10.1016/j.freeradbiomed.2004.09.030] [Citation(s) in RCA: 202] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2004] [Accepted: 09/22/2004] [Indexed: 12/31/2022]
Abstract
In addition to powering energy needs of the cell, mitochondria function as pivotal integrators of cell survival/death signals. In recent years, numerous studies indicate that each of the major kinase signaling pathways can be stimulated to target the mitochondrion. These include protein kinase A, protein kinase B/Akt, protein kinase C, extracellular signal-regulated protein kinase, c-Jun N-terminal kinase, and p38 mitogen-activated protein kinase. Although most studies focus on phosphorylation of pro- and antiapoptotic proteins (BAD, Bax, Bcl-2, Bcl-xL), kinase-mediated regulation of complex I activity, anion and cation channels, metabolic enzymes, and Mn-SOD mRNA has also been reported. Recent identification of a number of scaffold proteins (AKAP, PICK, Sab) that bring specific kinases to the cytoplasmic surface of mitochondria further emphasizes the importance of mitochondrial kinase signaling. Immunogold electron microscopy, subcellular fractionation and immunofluorescence studies demonstrate the presence of kinases within subcompartments of the mitochondrion, following diverse stimuli and in neurodegenerative diseases. Given the sensitivity of these signaling pathways to reactive oxygen and nitrogen species, in situ activation of mitochondrial kinases may represent a potent reverse-signaling mechanism for communication of mitochondrial status to the rest of the cell.
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Affiliation(s)
- Craig Horbinski
- Division of Neuropathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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Brookes PS, Yoon Y, Robotham JL, Anders MW, Sheu SS. Calcium, ATP, and ROS: a mitochondrial love-hate triangle. Am J Physiol Cell Physiol 2004; 287:C817-33. [PMID: 15355853 DOI: 10.1152/ajpcell.00139.2004] [Citation(s) in RCA: 1865] [Impact Index Per Article: 93.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The mitochondrion is at the core of cellular energy metabolism, being the site of most ATP generation. Calcium is a key regulator of mitochondrial function and acts at several levels within the organelle to stimulate ATP synthesis. However, the dysregulation of mitochondrial Ca2+homeostasis is now recognized to play a key role in several pathologies. For example, mitochondrial matrix Ca2+overload can lead to enhanced generation of reactive oxygen species, triggering of the permeability transition pore, and cytochrome c release, leading to apoptosis. Despite progress regarding the independent roles of both Ca2+and mitochondrial dysfunction in disease, the molecular mechanisms by which Ca2+can elicit mitochondrial dysfunction remain elusive. This review highlights the delicate balance between the positive and negative effects of Ca2+and the signaling events that perturb this balance. Overall, a “two-hit” hypothesis is developed, in which Ca2+plus another pathological stimulus can bring about mitochondrial dysfunction.
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Affiliation(s)
- Paul S Brookes
- University of Rochester Medical Center, 601 Elmwood Ave., Box 711, Rochester, NY 14642, USA
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Lima L, Cubillos S. Taurine-stimulated outgrowth from the retina is impaired by protein kinase C activators and phosphatase inhibitors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 442:423-30. [PMID: 9635059 DOI: 10.1007/978-1-4899-0117-0_52] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Taurine increases neurite elongation of post-crush goldfish retinal explants, as well as the number of outgrowing isolated cells from goldfish and rat retina in culture. The trophic effect of taurine is related to an elevation in calcium flux rather than increased cell proliferation. Since taurine regulates phosphorylation in rat retina, we investigated if this process could be involved in the mechanism of taurine action on outgrowth. Control and taurine-supplemented post-crush goldfish retinal explants were cultured in the presence of protein kinase C activators or phosphatase inhibitors, and the length of neurites was measured after five days in culture. In some cases, there was an inhibition of the stimulatory effect of taurine without a modification in basal outgrowth. In others, outgrowth of control explants was also reduced. A certain level of protein phosphorylation seems to be critical for the trophic effect of taurine in the retina.
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Affiliation(s)
- L Lima
- Laboratorio de Neuroquímica, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela
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