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Camacho-Pereira J, Lai de Souza LO, Chichierchio MS, Rodrigues-Chaves C, Lomba LDS, Fonseca-Oliveira M, Carvalho-Mendonça D, Silva-Rodrigues T, Galina A. The NADase CD38 may not dictate NAD levels in brain mitochondria of aged mice but regulates hydrogen peroxide generation. Free Radic Biol Med 2023; 209:29-39. [PMID: 37774804 DOI: 10.1016/j.freeradbiomed.2023.09.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/26/2023] [Accepted: 09/27/2023] [Indexed: 10/01/2023]
Abstract
Aging is a time-related functional decline that affects many species. One of the hallmarks of aging is mitochondrial dysfunction, which leads to metabolic decline. The NAD decline during aging, in several tissues, correlates with increase in NADase activity of CD38. Knock out or pharmacological inhibition of CD38 activity can rescue mitochondrial function in several tissues, however, the role of CD38 in controlling NAD levels and metabolic function in the aging brain is unknown. In this work, we investigated CD38 NADase activity controlling NAD levels and mitochondrial function in mice brain with aging. We demonstrate that NADase activity of CD38 does not dictate NAD total levels in brain of aging mice and does not control mitochondrial oxygen consumption nor other oxygen parameters markers of mitochondrial dysfunction. However, for the first time we show that CD38 regulates hydrogen peroxide (H2O2) generation, one of the reactive oxygen species (ROS) in aging brain, through regulation of pyruvate dehydrogenase and alfa-ketoglutarate dehydrogenase, as mitochondria H2O2 leakage sites. The effect may be related to mitochondrial calcium handling differences in CD38 absence. Our study highlights a novel role of CD38 in brain energy metabolism and aging.
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Affiliation(s)
- Juliana Camacho-Pereira
- Laboratório de Biologia Molecular de Leveduras, Instituto de Bioquímica Médica Leopoldo de Meis, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Cidade Universitária, Av. Carlos Chagas Filho 373, Ilha do Fundão, Rio de Janeiro, 21941-590, Brazil.
| | - Leonardo Osbourne Lai de Souza
- Laboratório de Biologia Molecular de Leveduras, Instituto de Bioquímica Médica Leopoldo de Meis, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Cidade Universitária, Av. Carlos Chagas Filho 373, Ilha do Fundão, Rio de Janeiro, 21941-590, Brazil.
| | - Marina Santos Chichierchio
- Laboratório de Biologia Molecular de Leveduras, Instituto de Bioquímica Médica Leopoldo de Meis, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Cidade Universitária, Av. Carlos Chagas Filho 373, Ilha do Fundão, Rio de Janeiro, 21941-590, Brazil.
| | - Camila Rodrigues-Chaves
- Laboratório de Bioenergética e Fisiologia Mitocondrial, Instituto de Bioquímica Médica Leopoldo de Meis, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Cidade Universitária, Av. Carlos Chagas Filho 373, Ilha do Fundão, Rio de Janeiro, 21941-590, Brazil.
| | - Luiza de Sousa Lomba
- Laboratório de Bioenergética e Fisiologia Mitocondrial, Instituto de Bioquímica Médica Leopoldo de Meis, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Cidade Universitária, Av. Carlos Chagas Filho 373, Ilha do Fundão, Rio de Janeiro, 21941-590, Brazil.
| | - Manoel Fonseca-Oliveira
- Laboratório de Bioenergética e Fisiologia Mitocondrial, Instituto de Bioquímica Médica Leopoldo de Meis, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Cidade Universitária, Av. Carlos Chagas Filho 373, Ilha do Fundão, Rio de Janeiro, 21941-590, Brazil.
| | - Daniel Carvalho-Mendonça
- Laboratório de Biologia Molecular de Leveduras, Instituto de Bioquímica Médica Leopoldo de Meis, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Cidade Universitária, Av. Carlos Chagas Filho 373, Ilha do Fundão, Rio de Janeiro, 21941-590, Brazil.
| | - Thaia Silva-Rodrigues
- Laboratório de Bioenergética e Fisiologia Mitocondrial, Instituto de Bioquímica Médica Leopoldo de Meis, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Cidade Universitária, Av. Carlos Chagas Filho 373, Ilha do Fundão, Rio de Janeiro, 21941-590, Brazil.
| | - Antonio Galina
- Laboratório de Bioenergética e Fisiologia Mitocondrial, Instituto de Bioquímica Médica Leopoldo de Meis, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Cidade Universitária, Av. Carlos Chagas Filho 373, Ilha do Fundão, Rio de Janeiro, 21941-590, Brazil.
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Navickaitė D, Ruzgys P, Maciulevičius M, Dijk G, O'Connor RP, Šatkauskas S. Ca 2+ roles in electroporation-induced changes of cancer cell physiology: From membrane repair to cell death. Bioelectrochemistry 2021; 142:107927. [PMID: 34425390 DOI: 10.1016/j.bioelechem.2021.107927] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 08/06/2021] [Accepted: 08/10/2021] [Indexed: 12/17/2022]
Abstract
The combination of Ca2+ ions and electroporation has gained attention as potential alternative to electrochemotherapy. Ca2+ is an important component of the cell membrane repair system and its presence directly influences the dynamics of the pore cycle after electroporation which can be exploited for cancer therapies. Here, the influence of Ca2+ concentration is investigated on small molecule electrotransfer and release of Calcein from 4T1, MX-1, B16F10, U87 cancer cells after cell exposure to microsecond electric pulses. Moreover, we investigated simultaneous molecule electrotransfer and intracellular calcium ion influx when media was supplemented with different Ca2+ concentrations. Results show that increased concentrations of calcium ions reduce the electrotransfer of small molecules to different lines of cancer cells as well as the release of Calcein. These effects are related with an enhanced membrane repair mechanism. Overall, we show that the efficiency of molecular electrotransfer can be controlled by regulating Ca2+ concentration in the electroporation medium. For the first time, the cause of cancer cell death in vitro from 1 mM CaCl2 concentrations is related to the irreversible loss of Ca2+ homeostasis after cell electroporation. Our findings provide fundamental insight on the mechanisms of Ca2+ electroporation that might lead to improved therapeutic outcomes.
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Abstract
The pioneering work of Richard Altman on the presence of mitochondria in cells set in motion a field of research dedicated to uncovering the secrets of the mitochondria. Despite limitations in studying the structure and function of the mitochondria, advances in our understanding of this organelle prompted the development of potential treatments for various diseases, from neurodegenerative conditions to muscular dystrophy and cancer. As the powerhouses of the cell, the mitochondria represent the essence of cellular life and as such, a selective advantage for cancer cells. Much of the function of the mitochondria relies on Ca2+ homeostasis and the presence of effective Ca2+ signaling to maintain the balance between mitochondrial function and dysfunction and subsequently, cell survival. Ca2+ regulates the mitochondrial respiration rate which in turn increases ATP synthesis, but too much Ca2+ can also trigger the mitochondrial apoptosis pathway; however, cancer cells have evolved mechanisms to modulate mitochondrial Ca2+ influx and efflux in order to sustain their metabolic demand and ensure their survival. Therefore, targeting the mitochondrial Ca2+ signaling involved in the bioenergetic and apoptotic pathways could serve as potential approaches to treat cancer patients. This chapter will review the role of Ca2+ signaling in mediating the function of the mitochondria and its involvement in health and disease with special focus on the pathophysiology of cancer.
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Affiliation(s)
- Andra M Sterea
- Departments of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
| | - Yassine El Hiani
- Departments of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada.
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Liu C, Shao G, Lu Y, Xue M, Liang F, Zhang Z, Bai L. Parathyroid Hormone-Related Protein (1-40) Enhances Calcium Uptake in Rat Enterocytes Through PTHR1 Receptor and Protein Kinase Cα/β Signaling. Cell Physiol Biochem 2018; 51:1695-1709. [PMID: 30504697 DOI: 10.1159/000495674] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 11/22/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Parathyroid hormone-related protein (PTHrP) is implicated in regulating calcium homeostasis in vertebrates, including sea bream, chick, and mammals. However, the molecular mechanism underlying the function of PTHrP in regulating calcium transport is still not fully investigated. This study aimed to investigate the effect of PTHrP on the calcium uptake and its underlying molecular mechanism in rat enterocytes. METHODS The rat intestinal epithelial cell line (IEC-6) was used. Calcium uptake was determined by using the fluo-4 acetoxymethyl ester fluorescence method. The expression levels of RNAs and proteins was assessed by RT-PCR and Western-blot, respectively. RESULTS PTHrP (1-40) induced rapid calcium uptake in enterocytes in a dose-dependent manner. PTHrP (1-40) up-regulated parathyroid hormone 1 receptor (PTHR1) protein but not 1,25D3-MARRS receptor. Pre-treatment of anti- PTHR1 antibody abolished the PTHrP (1-40)-induced calcium uptake. PTHrP (1-40) significantly up-regulated four transcellular calcium transporter proteins, potential vanilloid member 6 (TRPV6), calbindin-D9k (CaBP-D9k), sodium-calcium exchanger 1 (NCX1) and plasma membrane calcium ATPase 1 (PMCA1), in a dose- and time-dependent manner. Pre-treatment with TRPV6 or CaBP-D9k antibodies or knockout of rat TRPV6 or CaBP-D9k markedly inhibited PTHrP (1-40)-induced calcium uptake, whereas inhibition of NCX or PMCA1 by antibodies or inhibitors had no effect on PTHrP(1-40)-induced calcium uptake. Furthermore, PTHrP (1-40) treatment up-regulated protein levels of protein kinase C (PKC α/β) and protein kinase A (PKA). Pretreatment of PKC α/β inhibitor (but not PKA inhibitor) inhibited PTHrP (1-40)-induced calcium uptake. CONCLUSION PTHrP (1-40) stimulates calcium uptake via PTHR1 receptor and PKC α/β signaling pathway in rat enterocytes, and calcium transporters TRPV6 and CaBP-D9k are necessary for this stimulatory effect.
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Affiliation(s)
- Cuiping Liu
- Department of Critical Care Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China.,Guang Dong Provincial Key Laboratory of Gastroenterology Department for Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Guoli Shao
- Department of General Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Yirong Lu
- Department of Critical Care Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Minmin Xue
- Guang Dong Provincial Key Laboratory of Gastroenterology Department for Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Fenfen Liang
- Guang Dong Provincial Key Laboratory of Gastroenterology Department for Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Zhenshu Zhang
- Guang Dong Provincial Key Laboratory of Gastroenterology Department for Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Lan Bai
- Guang Dong Provincial Key Laboratory of Gastroenterology Department for Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou,
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Brustovetsky N. Mutant Huntingtin and Elusive Defects in Oxidative Metabolism and Mitochondrial Calcium Handling. Mol Neurobiol 2016; 53:2944-2953. [PMID: 25941077 PMCID: PMC4635103 DOI: 10.1007/s12035-015-9188-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 04/22/2015] [Indexed: 01/13/2023]
Abstract
Elongation of a polyglutamine (polyQ) stretch in huntingtin protein (Htt) is linked to Huntington's disease (HD) pathogenesis. The mutation in Htt correlates with neuronal dysfunction in the striatum and cerebral cortex and eventually leads to neuronal cell death. The exact mechanisms of the injurious effect of mutant Htt (mHtt) on neurons are not completely understood but might include aberrant gene transcription, defective autophagy, abnormal mitochondrial biogenesis, anomalous mitochondrial dynamics, and trafficking. In addition, deficiency in oxidative metabolism and defects in mitochondrial Ca(2+) handling are considered essential contributing factors to neuronal dysfunction in HD and, consequently, in HD pathogenesis. Since the discovery of the mutation in Htt, the questions whether mHtt affects oxidative metabolism and mitochondrial Ca(2+) handling and, if it does, what mechanisms could be involved were in focus of numerous investigations. However, despite significant research efforts, the detrimental effect of mHtt and the mechanisms by which mHtt might impair oxidative metabolism and mitochondrial Ca(2+) handling remain elusive. In this paper, I will briefly review studies aimed at clarifying the consequences of mHtt interaction with mitochondria and discuss experimental results supporting or arguing against the mHtt effects on oxidative metabolism and mitochondrial Ca(2+) handling.
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Affiliation(s)
- Nickolay Brustovetsky
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, 635 Barnhill Dr., Medical Science Bldg 547, Indianapolis, IN, 46202, USA.
- Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
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Blomeyer CA, Bazil JN, Stowe DF, Dash RK, Camara AKS. Mg(2+) differentially regulates two modes of mitochondrial Ca(2+) uptake in isolated cardiac mitochondria: implications for mitochondrial Ca(2+) sequestration. J Bioenerg Biomembr 2016; 48:175-88. [PMID: 26815005 DOI: 10.1007/s10863-016-9644-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 01/12/2016] [Indexed: 12/14/2022]
Abstract
The manner in which mitochondria take up and store Ca(2+) remains highly debated. Recent experimental and computational evidence has suggested the presence of at least two modes of Ca(2+) uptake and a complex Ca(2+) sequestration mechanism in mitochondria. But how Mg(2+) regulates these different modes of Ca(2+) uptake as well as mitochondrial Ca(2+) sequestration is not known. In this study, we investigated two different ways by which mitochondria take up and sequester Ca(2+) by using two different protocols. Isolated guinea pig cardiac mitochondria were exposed to varying concentrations of CaCl2 in the presence or absence of MgCl2. In the first protocol, A, CaCl2 was added to the respiration buffer containing isolated mitochondria, whereas in the second protocol, B, mitochondria were added to the respiration buffer with CaCl2 already present. Protocol A resulted first in a fast transitory uptake followed by a slow gradual uptake. In contrast, protocol B only revealed a slow and gradual Ca(2+) uptake, which was approximately 40 % of the slow uptake rate observed in protocol A. These two types of Ca(2+) uptake modes were differentially modulated by extra-matrix Mg(2+). That is, Mg(2+) markedly inhibited the slow mode of Ca(2+) uptake in both protocols in a concentration-dependent manner, but not the fast mode of uptake exhibited in protocol A. Mg(2+) also inhibited Na(+)-dependent Ca(2+) extrusion. The general Ca(2+) binding properties of the mitochondrial Ca(2+) sequestration system were reaffirmed and shown to be independent of the mode of Ca(2+) uptake, i.e. through the fast or slow mode of uptake. In addition, extra-matrix Mg(2+) hindered Ca(2+) sequestration. Our results indicate that mitochondria exhibit different modes of Ca(2+) uptake depending on the nature of exposure to extra-matrix Ca(2+), which are differentially sensitive to Mg(2+). The implications of these findings in cardiomyocytes are discussed.
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Affiliation(s)
- Christoph A Blomeyer
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Jason N Bazil
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, USA.,Biotechnology and Bioengineering Center, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - David F Stowe
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.,Department of Biomedical Engineering, Marquette University, Milwaukee, WI, 53233, USA.,Research Service, Zablocki Veterans Affairs Medical Center, Milwaukee, WI, 53295, USA
| | - Ranjan K Dash
- Biotechnology and Bioengineering Center, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.,Department of Biomedical Engineering, Marquette University, Milwaukee, WI, 53233, USA
| | - Amadou K S Camara
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
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Baniene R, Trumbeckas D, Kincius M, Pauziene N, Raudone L, Jievaltas M, Trumbeckaite S. Short ischemia induces rat kidney mitochondria dysfunction. J Bioenerg Biomembr 2016; 48:77-85. [PMID: 26782060 DOI: 10.1007/s10863-016-9643-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 01/12/2016] [Indexed: 11/24/2022]
Abstract
Renal artery clamping itself induces renal ischemia which subsequently causes renal cell injury and can lead to renal failure. The duration of warm ischemia that would be safe for postoperative kidney function during partial nephrectomy remains under investigations. Mitochondria play an important role in pathophysiology of ischemia-reperfusion induced kidney injury, however relation between ischemia time and mitochondrial dysfunction are not fully elucidated. Thus, the effects of renal ischemia (20 min, 40 min and 60 min) on mitochondrial functions were investigated by using in vitro rat ischemia model. Thus, electronmicroscopy showed that at short (20 min) ischemia mitochondria start to swell and the damage increases with the duration of ischemia. In accordance with this, a significant decrease in mitochondrial oxidative phosphorylation capacity was observed already after 20 min of ischemia with both, complex I dependent substrate glutamate/malate (52%) and complex II dependent substrate succinate (44%) which further decreased with the prolonged time of ischemia. The diminished state 3 respiration rate was associated with the decrease in mitochondrial Complex I activity and the release of cytochrome c. Mitochondrial Ca(2+) uptake was diminished by 37-49% after 20-60 min of ischemia and caspase-3 activation increased by 1.15-2.32-fold as compared to control. LDH activity changed closely with increasing time of renal ischemia. In conclusion, even short time (20 min) of warm ischemia in vitro leads to renal mitochondrial injury which increases progressively with the duration of ischemia.
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Affiliation(s)
- Rasa Baniene
- Neuroscience Institute, Lithuanian University of Health Sciences, Eiveniu str. 4, LT-50009, Kaunas, Lithuania. .,Department of Biochemistry, Medical Academy, Lithuanian University of Health Sciences, Eiveniu str. 4, LT-50009, Kaunas, Lithuania.
| | - Darius Trumbeckas
- Department of Urology, Medical Academy, Lithuanian University of Health Sciences, Eivenių g. 2, LT-50009, Kaunas, Lithuania
| | - Marius Kincius
- Department of Urology, Medical Academy, Lithuanian University of Health Sciences, Eivenių g. 2, LT-50009, Kaunas, Lithuania
| | - Neringa Pauziene
- Institute of Anatomy, Lithuanian University of Health Sciences Kaunas, Lithuania, Mickeviciaus str. 9, LT-44307, Kaunas, Lithuasnia
| | - Lina Raudone
- Department of Pharmacognosy, Medical Academy, Lithuanian University of Health Sciences, Eiveniu str. 4, LT-50009, Kaunas, Lithuania
| | - Mindaugas Jievaltas
- Department of Urology, Medical Academy, Lithuanian University of Health Sciences, Eivenių g. 2, LT-50009, Kaunas, Lithuania
| | - Sonata Trumbeckaite
- Neuroscience Institute, Lithuanian University of Health Sciences, Eiveniu str. 4, LT-50009, Kaunas, Lithuania.,Department of Pharmacognosy, Medical Academy, Lithuanian University of Health Sciences, Eiveniu str. 4, LT-50009, Kaunas, Lithuania
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Abstract
The various isoforms of the sarco/endoplasmic reticulum Ca(2+) ATPase (SERCA) are responsible for the Ca(2+) uptake from the cytosol into the endoplasmic or sarcoplasmic reticulum (ER/SR). In some tissues, the activity of SERCA can be modulated by binding partners, such as phospholamban and sarcolipin. The activity of SERCA can be characterized by its apparent affinity for Ca(2+) as well as maximal enzymatic velocity. Both parameters can be effectively determined by the protocol described here. Specifically, we describe the measurement of the rate of oxalate-facilitated (45)Ca uptake into the SR of crude mouse ventricular homogenates. This protocol can easily be adapted for different tissues and animal models as well as cultured cells.
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Affiliation(s)
- Philip A Bidwell
- Department of Pharmacology and Cell Biophysics, College of Medicine, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Evangelia G Kranias
- Department of Pharmacology and Cell Biophysics, College of Medicine, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA.
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Abstract
Bioenergetics has become central to our understanding of pathological mechanisms as well as the development of new therapeutic strategies and as a tool for gauging disease progression in neurodegeneration, diabetes, cancer, and cardiovascular disease. The view is emerging that inner mitochondrial membrane (IMM) cation channels have a profound effect on mitochondrial function and, consequently, on the metabolic state and survival of the whole cell. Since disruption of the sustained integrity of mitochondria is strongly linked to human disease, pharmacological intervention offers a new perspective concerning neurodegenerative and cardiovascular diseases as well as cancer. This review summarizes our current knowledge regarding IMM cation channels and their roles under physiological conditions as well as in cancer, with special emphasis on potassium channels and the mammalian mitochondrial calcium uniporter.
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10
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da Rosa LA, Escott GM, Cavalari FC, Schneider CMM, de Fraga LS, Loss EDS. Non-classical effects of androgens on testes from neonatal rats. Steroids 2015; 93:32-8. [PMID: 25449768 DOI: 10.1016/j.steroids.2014.10.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 08/12/2014] [Accepted: 10/25/2014] [Indexed: 01/08/2023]
Abstract
The intratesticular testosterone concentration is high during the early postnatal period although the intracellular androgen receptor expression (iAR) is still absent in Sertoli cells (SCs). This study aimed to evaluate the non-classical effects of testosterone and epitestosterone on calcium uptake and the electrophysiological effects of testosterone (1μM) on SCs from rats on postnatal day (pnd) 3 and 4 with lack of expression of the iAR. In addition, crosstalk on the electrophysiological effects of testosterone and epitestosterone with follicle stimulating hormone (FSH) in SCs from 15-day-old rats was evaluated. The isotope (45)Ca(2+) was utilized to evaluate the effects of testosterone and epitestosterone in calcium uptake. The membrane potential of SCs was recorded using a standard single microelectrode technique. No immunoreaction concerning the iAR was observed in SCs on pnd 3 and 4. At this age, both testosterone and epitestosterone increased the (45)Ca(2+) uptake. Testosterone promoted membrane potential depolarization of SCs on pnd 4. FSH application followed by testosterone and epitestosterone reduced the depolarization of the two hormones. Application of epitestosterone 5 min after FSH resulted in a delay of epitestosterone-promoted depolarization. The cell resistance was also reduced. Thus, in SCs from neonatal Wistar rats, both testosterone and epitestosterone act through a non-classical mechanism stimulating calcium uptake in whole testes, and testosterone produces a depolarizing effect on SC membranes. Testosterone and epitestosterone stimulates non-classical actions via a membrane mechanism, which is independent of iAR. FSH and testosterone/epitestosterone affect each other's electrophysiological responses suggesting crosstalk between the intracellular signaling pathways.
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Affiliation(s)
- Luciana Abreu da Rosa
- Laboratório de Endocrinologia Experimental e Eletrofisiologia, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Brazil
| | - Gustavo Monteiro Escott
- Laboratório de Endocrinologia Experimental e Eletrofisiologia, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Brazil
| | - Fernanda Carvalho Cavalari
- Laboratório de Endocrinologia Experimental e Eletrofisiologia, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Brazil
| | - Clara Maria Müller Schneider
- Laboratório de Endocrinologia Experimental e Eletrofisiologia, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Brazil
| | - Luciano Stürmer de Fraga
- Laboratório de Endocrinologia Experimental e Eletrofisiologia, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Brazil
| | - Eloísa da Silveira Loss
- Laboratório de Endocrinologia Experimental e Eletrofisiologia, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Brazil.
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11
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Brun LR, Brance ML, Lombarte M, Lupo M, Di Loreto VE, Rigalli A. Regulation of intestinal calcium absorption by luminal calcium content: role of intestinal alkaline phosphatase. Mol Nutr Food Res 2014; 58:1546-51. [PMID: 24753180 DOI: 10.1002/mnfr.201300686] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 02/28/2014] [Accepted: 03/06/2014] [Indexed: 01/28/2023]
Abstract
SCOPE Intestinal alkaline phosphatase is a brush border enzyme that is stimulated by calcium. Inhibition of intestinal alkaline phosphatase increases intestinal calcium absorption. We hypothesized that intestinal alkaline phosphatase acts as a minute-to-minute regulatory mechanism of calcium entry. The aim of this study was to evaluate the mechanism by which intestinal luminal calcium controls intestinal calcium absorption. METHODS AND RESULTS We performed kinetic studies with purified intestinal alkaline phosphatase and everted duodenal sacs and showed that intestinal alkaline phosphatase modifies the luminal pH as a function of enzyme concentration and calcium luminal content. A decrease in pH occurred simultaneously with a decrease in calcium absorption. The inhibition of intestinal alkaline phosphatase by l-phenylalanine caused an increase in calcium absorption. This effect was also confirmed in calcium uptake experiments with isolated duodenal cells. CONCLUSION Changes in luminal pH arising from intestinal alkaline phosphatase activity induced by luminal calcium concentration modulate intestinal calcium absorption.
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Affiliation(s)
- Lucas R Brun
- Bone Biology Laboratory, School of Medicine, Rosario National University, Argentina
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12
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Escott GM, de Castro AL, Jacobus AP, Loss ES. Insulin and IGF-I actions on IGF-I receptor in seminiferous tubules from immature rats. Biochim Biophys Acta 2014; 1838:1332-7. [PMID: 24530896 DOI: 10.1016/j.bbamem.2014.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 01/14/2014] [Accepted: 02/01/2014] [Indexed: 11/17/2022]
Abstract
Insulin and insulin-like growth factor 1 (IGF-I) are capable of activating similar intracellular pathways. Insulin acts mainly through its own receptor, but can also activate the IGF-I receptor (IGF-IR). The aim of this study was to investigate the involvement of the IGF-IR in the effects of insulin and IGF-I on the membrane potential of immature Sertoli cells in whole seminiferous tubules, as well as on calcium, amino acid, and glucose uptake in testicular tissue of immature rats. The membrane potential of the Sertoli cells was recorded using a standard single microelectrode technique. In calcium uptake experiments, the testes were pre-incubated with (45)Ca(2+), with or without JB1 (1 μg/mL), and then incubated with insulin (100 nM) or IGF-I (15 nM). In amino acid and glucose uptake experiments, the gonads were pre-incubated with or without JB1 (1 μg/mL) and then incubated with radiolabeled amino acid or glucose analogues in the presence of insulin (100 nM) or IGF-I (15 nM). The blockade of IGF-IR with JB1 prevented the depolarising effects of both insulin and IGF-I on membrane potential, as well as the effect of insulin on calcium uptake. JB1 also inhibited the effects of insulin and IGF-I on glucose uptake. The effect of IGF-I on amino acid transport was inhibited in the presence of JB1, whereas the effect of insulin was not. We concluded that while IGF-I seems to act mainly through its cognate receptor to induce membrane depolarisation and calcium, amino acid and glucose uptake, insulin appears to be able to elicit its effects through IGF-IR, in seminiferous tubules from immature rats.
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Affiliation(s)
- Gustavo Monteiro Escott
- Laboratório de Endocrinologia Experimental e Eletrofisiologia, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Brazil
| | - Alexandre Luz de Castro
- Laboratório de Endocrinologia Experimental e Eletrofisiologia, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Brazil
| | | | - E S Loss
- Laboratório de Endocrinologia Experimental e Eletrofisiologia, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Brazil.
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