351
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Auger C, Alhasawi A, Contavadoo M, Appanna VD. Dysfunctional mitochondrial bioenergetics and the pathogenesis of hepatic disorders. Front Cell Dev Biol 2015; 3:40. [PMID: 26161384 PMCID: PMC4479819 DOI: 10.3389/fcell.2015.00040] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Accepted: 06/12/2015] [Indexed: 12/18/2022] Open
Abstract
The liver is involved in a variety of critical biological functions including the homeostasis of glucose, fatty acids, amino acids, and the synthesis of proteins that are secreted in the blood. It is also at the forefront in the detoxification of noxious metabolites that would otherwise upset the functioning of the body. As such, this vital component of the mammalian system is exposed to a notable quantity of toxicants on a regular basis. It therefore comes as no surprise that there are over a hundred disparate hepatic disorders, encompassing such afflictions as fatty liver disease, hepatitis, and liver cancer. Most if not all of liver functions are dependent on energy, an ingredient that is primarily generated by the mitochondrion, the power house of all cells. This organelle is indispensable in providing adenosine triphosphate (ATP), a key effector of most biological processes. Dysfunctional mitochondria lead to a shortage in ATP, the leakage of deleterious reactive oxygen species (ROS), and the excessive storage of fats. Here we examine how incapacitated mitochondrial bioenergetics triggers the pathogenesis of various hepatic diseases. Exposure of liver cells to detrimental environmental hazards such as oxidative stress, metal toxicity, and various xenobiotics results in the inactivation of crucial mitochondrial enzymes and decreased ATP levels. The contribution of the latter to hepatic disorders and potential therapeutic cues to remedy these conditions are elaborated.
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Affiliation(s)
- Christopher Auger
- Faculty of Science and Engineering, Laurentian University Greater Sudbury, ON, Canada
| | - Azhar Alhasawi
- Faculty of Science and Engineering, Laurentian University Greater Sudbury, ON, Canada
| | - Manuraj Contavadoo
- Faculty of Science and Engineering, Laurentian University Greater Sudbury, ON, Canada
| | - Vasu D Appanna
- Faculty of Science and Engineering, Laurentian University Greater Sudbury, ON, Canada
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352
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Glutathione Supplementation Attenuates Oxidative Stress and Improves Vascular Hyporesponsiveness in Experimental Obstructive Jaundice. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:486148. [PMID: 26161237 PMCID: PMC4487904 DOI: 10.1155/2015/486148] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 01/31/2015] [Accepted: 01/31/2015] [Indexed: 12/01/2022]
Abstract
We investigated the protective effects and mechanism of glutathione (GSH) on vascular hyporesponsiveness induced by bile duct ligation (BDL) in a rat model. Seventy-two male Sprague-Dawley rats were randomly divided into four groups: a NS group, a GSH group, a BDL + NS group, and a BDL + GSH group. GSH was administrated into rats in the GSH and BDL + GSH groups by gastric gavage. An equal volume of normal saline was, respectively, given in the NS group and BDL + NS group. Blood was gathered for serological determination and thoracic aorta rings were isolated for measurement of isometric tension. Obstructive jaundice led to a significant increase in the serum total bilirubin, AST, and ALT levels. The proinflammatory cytokines levels (TNF-α and IL-1β), concentration of NO, and oxidative stress markers (MDA and 3-NT) were increased as well. All of those were reduced by the treatment of GSH. Meanwhile, contraction of aorta rings to NA and vasorelaxation to ACh or SNP in the BDL group rats were markedly decreased, while GSH administration reversed this change. Our findings suggested that GSH supplementation attenuated overexpressed ONOO(−) from the reaction of excessive NO with O2∙- and protected against obstructive jaundice-induced vascular hyporesponsiveness in rats.
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353
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Yin J, Ren W, Yang G, Duan J, Huang X, Fang R, Li C, Li T, Yin Y, Hou Y, Kim SW, Wu G. L-Cysteine metabolism and its nutritional implications. Mol Nutr Food Res 2015; 60:134-46. [PMID: 25929483 DOI: 10.1002/mnfr.201500031] [Citation(s) in RCA: 205] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 04/08/2015] [Accepted: 04/23/2015] [Indexed: 01/17/2023]
Abstract
L-Cysteine is a nutritionally semiessential amino acid and is present mainly in the form of L-cystine in the extracellular space. With the help of a transport system, extracellular L-cystine crosses the plasma membrane and is reduced to L-cysteine within cells by thioredoxin and reduced glutathione (GSH). Intracellular L-cysteine plays an important role in cellular homeostasis as a precursor for protein synthesis, and for production of GSH, hydrogen sulfide (H(2)S), and taurine. L-Cysteine-dependent synthesis of GSH has been investigated in many pathological conditions, while the pathway for L-cysteine metabolism to form H(2)S has received little attention with regard to prevention and treatment of disease in humans. The main objective of this review is to highlight the metabolic pathways of L-cysteine catabolism to GSH, H(2)S, and taurine, with special emphasis on therapeutic and nutritional use of L-cysteine to improve the health and well-being of animals and humans.
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Affiliation(s)
- Jie Yin
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock, Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wenkai Ren
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock, Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Guan Yang
- Department of Animal Science, University of Florida, Gainesville, FL, USA
| | - Jielin Duan
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock, Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xingguo Huang
- Department of Animal Science, Hunan Agriculture University, Changsha, China
| | - Rejun Fang
- Department of Animal Science, Hunan Agriculture University, Changsha, China
| | - Chongyong Li
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock, Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China
| | - Tiejun Li
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock, Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China
| | - Yulong Yin
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock, Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China
- School of Life Sciences, Hunan Normal University, Changsha, China
| | - Yongqing Hou
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan Polytechnic University, Wuhan, China
| | - Sung Woo Kim
- Department of Animal Science, North Carolina State University, Raleigh, NC, USA
| | - Guoyao Wu
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock, Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan Polytechnic University, Wuhan, China
- Department of Animal Science, Texas A&M University, College Station, TX, USA
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354
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Protective effects of dietary avocado oil on impaired electron transport chain function and exacerbated oxidative stress in liver mitochondria from diabetic rats. J Bioenerg Biomembr 2015; 47:337-53. [PMID: 26060181 DOI: 10.1007/s10863-015-9614-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Accepted: 05/29/2015] [Indexed: 02/07/2023]
Abstract
Electron transport chain (ETC) dysfunction, excessive ROS generation and lipid peroxidation are hallmarks of mitochondrial injury in the diabetic liver, with these alterations also playing a role in the development of non-alcoholic fatty liver disease (NAFLD). Enhanced mitochondrial sensitivity to lipid peroxidation during diabetes has been also associated to augmented content of C22:6 in membrane phospholipids. Thus, we aimed to test whether avocado oil, a rich source of C18:1 and antioxidants, attenuates the deleterious effects of diabetes on oxidative status of liver mitochondria by decreasing unsaturation of acyl chains of membrane lipids and/or by improving ETC functionality and decreasing ROS generation. Streptozocin-induced diabetes elicited a noticeable increase in the content of C22:6, leading to augmented mitochondrial peroxidizability index and higher levels of lipid peroxidation. Mitochondrial respiration and complex I activity were impaired in diabetic rats with a concomitant increase in ROS generation using a complex I substrate. This was associated to a more oxidized state of glutathione, All these alterations were prevented by avocado oil except by the changes in mitochondrial fatty acid composition. Avocado oil did not prevented hyperglycemia and polyphagia although did normalized hyperlipidemia. Neither diabetes nor avocado oil induced steatosis. These results suggest that avocado oil improves mitochondrial ETC function by attenuating the deleterious effects of oxidative stress in the liver of diabetic rats independently of a hypoglycemic effect or by modifying the fatty acid composition of mitochondrial membranes. These findings might have also significant implications in the progression of NAFLD in experimental models of steatosis.
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355
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Gonçalves AC, Cortesão E, Oliveiros B, Alves V, Espadana AI, Rito L, Magalhães E, Lobão MJ, Pereira A, Nascimento Costa JM, Mota-Vieira L, Sarmento-Ribeiro AB. Oxidative stress and mitochondrial dysfunction play a role in myelodysplastic syndrome development, diagnosis, and prognosis: A pilot study. Free Radic Res 2015; 49:1081-94. [PMID: 25968944 DOI: 10.3109/10715762.2015.1035268] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The imbalance between reactive oxygen species (ROS) production and their elimination by antioxidants leads to oxidative stress. Depending on their concentration, ROS can trigger apoptosis or stimulate cell proliferation. We hypothesized that oxidative stress and mitochondrial dysfunction may participate not only in apoptosis detected in some myelodysplastic syndrome (MDS) patients, but also in increasing proliferation in other patients. We investigated the involvement of oxidative stress and mitochondrial dysfunction in MDS pathogenesis, as well as assessed their diagnostic and prognostic values. Intracellular peroxides, superoxide, superoxide/peroxides ratio, reduced glutathione (GSH), and mitochondrial membrane potential (Δψ(mit)) levels were analyzed in bone marrow cells from 27 MDS patients and 12 controls, by flow cytometry. We observed that all bone marrow cell types from MDS patients had increased intracellular peroxide levels and decreased GSH content, compared with control cells. Moreover, oxidative stress levels were MDS subtype- and risk group-dependent. Low-risk patients had the highest ROS levels, which can be related with their high apoptosis; and intermediate-2-risk patients had high Δψ(mit) that may be associated with their proliferative potential. GSH levels were negatively correlated with transfusion dependency, and peroxide levels were positively correlated with serum ferritin level. GSH content proved to be an accurate parameter to discriminate patients from controls. Finally, patients with high ROS or low GSH levels, as well as high superoxide/peroxides ratio had lower overall survival. Our results suggest that oxidative stress and mitochondrial dysfunction are involved in MDS development, and that oxidative stress parameters may constitute novel diagnosis and/or prognosis biomarkers for MDS.
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Affiliation(s)
- A C Gonçalves
- Laboratory of Oncobiology and Hematology, FMUC - Faculty of Medicine, University of Coimbra , Coimbra , Portugal
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356
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Pompella A, Corti A. Editorial: the changing faces of glutathione, a cellular protagonist. Front Pharmacol 2015; 6:98. [PMID: 26029106 PMCID: PMC4432574 DOI: 10.3389/fphar.2015.00098] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 04/20/2015] [Indexed: 01/19/2023] Open
Affiliation(s)
- Alfonso Pompella
- Department of Translational Research NTMC, University of Pisa Pisa, Italy
| | - Alessandro Corti
- Department of Translational Research NTMC, University of Pisa Pisa, Italy
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357
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Benson KF, Newman RA, Jensen GS. Antioxidant, anti-inflammatory, anti-apoptotic, and skin regenerative properties of an Aloe vera-based extract of Nerium oleander leaves (nae-8(®)). Clin Cosmet Investig Dermatol 2015; 8:239-48. [PMID: 26005354 PMCID: PMC4427598 DOI: 10.2147/ccid.s79871] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Objective The goal for this study was to evaluate the effects of an Aloe vera-based Nerium oleander extract (NAE-8®), compared to an extract of A. vera gel alone (ALOE), and to an aqueous extract of N. oleander (AQ-NOE) in bioassays pertaining to dermatologic potential with respect to antioxidant protection, anti-inflammatory effects, and cytokine profiles in vitro. Methods Cellular antioxidant protection was evaluated in three separate bioassays: The cellular antioxidant protection of erythrocytes (CAP-e) assay, protection of cellular viability and prevention of apoptosis, and protection of intracellular reduced glutathione levels, where the last two assays were performed using human primary dermal fibroblasts. Reduction of intracellular formation of reactive oxygen species (ROS) was tested using polymorphonuclear cells in the absence and presence of oxidative stress. Changes to cytokine and chemokine profiles when whole blood cells and human primary dermal fibroblasts were exposed to test products were determined using a 40-plex Luminex array as a method for exploring the potential cross-talk between circulating and skin-resident cells. Results The NAE-8® provided significantly better antioxidant protection in the CAP-e bioassay than AQ-NOE. NAE-8® and AQ-NOE both protected cellular viability and intracellular reduced glutathione, and reduced the ROS formation significantly when compared to control cells, both under inflamed and neutral culture conditions. ALOE showed minimal effect in these bioassays. In contrast to the NAE-8®, the AQ-NOE showed induction of inflammation in the whole blood cultures, as evidenced by the high induction of CD69 expression and secretion of a number of inflammatory cytokines. The treatment of dermal fibroblasts with NAE-8® resulted in selective secretion of cytokines involved in collagen and hyaluronan production as well as re-epithelialization during wound healing. Conclusion NAE-8®, a novel component of a commercial cosmetic product, showed beneficial antioxidant protection in several cellular models, without the induction of leukocyte activation and secretion of inflammatory cytokines. The biological efficacy of NAE-8® was unique from both ALOE and AQ-NOE.
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Affiliation(s)
| | - Robert A Newman
- University of Texas MD Anderson Cancer Center, Houston, TX, USA ; Nerium Biotechnology, Inc, San Antonio, TX, USA
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358
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Cermanova J, Kadova Z, Zagorova M, Hroch M, Tomsik P, Nachtigal P, Kudlackova Z, Pavek P, Dubecka M, Ceckova M, Staud F, Laho T, Micuda S. Boldine enhances bile production in rats via osmotic and farnesoid X receptor dependent mechanisms. Toxicol Appl Pharmacol 2015; 285:12-22. [PMID: 25771127 DOI: 10.1016/j.taap.2015.03.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 02/26/2015] [Accepted: 03/03/2015] [Indexed: 12/22/2022]
Abstract
Boldine, the major alkaloid from the Chilean Boldo tree, is used in traditional medicine to support bile production, but evidence to support this function is controversial. We analyzed the choleretic potential of boldine, including its molecular background. The acute- and long-term effects of boldine were evaluated in rats either during intravenous infusion or after 28-day oral treatment. Infusion of boldine instantly increased the bile flow 1.4-fold in healthy rats as well as in animals with Mrp2 deficiency or ethinylestradiol induced cholestasis. This effect was not associated with a corresponding increase in bile acid or glutathione biliary excretion, indicating that the effect is not related to stimulation of either bile acid dependent or independent mechanisms of bile formation and points to the osmotic activity of boldine itself. We subsequently analyzed bile production under conditions of changing biliary excretion of boldine after bolus intravenous administration and found strong correlations between both parameters. HPLC analysis showed that bile concentrations of boldine above 10 μM were required for induction of choleresis. Importantly, long-term pretreatment, when the bile collection study was performed 24-h after the last administration of boldine, also accelerated bile formation despite undetectable levels of the compound in bile. The effect paralleled upregulation of the Bsep transporter and increased biliary clearance of its substrates, bile acids. We consequently confirmed the ability of boldine to stimulate the Bsep transcriptional regulator, FXR receptor. In conclusion, our study clarified the mechanisms and circumstances surrounding the choleretic activity of boldine.
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Affiliation(s)
- Jolana Cermanova
- Department of Pharmacology, Charles University in Prague, Faculty of Medicine in Hradec Kralove, Czech Republic
| | - Zuzana Kadova
- Department of Pharmacology, Charles University in Prague, Faculty of Medicine in Hradec Kralove, Czech Republic; Deparment of Pharmacology and Toxicology, Charles University in Prague, Faculty of Pharmacy in Hradec Kralove, Czech Republic
| | - Marie Zagorova
- Department of Pharmacology, Charles University in Prague, Faculty of Medicine in Hradec Kralove, Czech Republic
| | - Milos Hroch
- Department of Pharmacology, Charles University in Prague, Faculty of Medicine in Hradec Kralove, Czech Republic; Department of Medical Biochemistry, Charles University in Prague, Faculty of Medicine in Hradec Kralove, Czech Republic
| | - Pavel Tomsik
- Department of Medical Biochemistry, Charles University in Prague, Faculty of Medicine in Hradec Kralove, Czech Republic
| | - Petr Nachtigal
- Department of Biological and Medical Sciences, Charles University in Prague, Faculty of Pharmacy in Hradec Kralove, Czech Republic
| | - Zdenka Kudlackova
- Department of Biological and Medical Sciences, Charles University in Prague, Faculty of Pharmacy in Hradec Kralove, Czech Republic
| | - Petr Pavek
- Deparment of Pharmacology and Toxicology, Charles University in Prague, Faculty of Pharmacy in Hradec Kralove, Czech Republic
| | - Michaela Dubecka
- Deparment of Pharmacology and Toxicology, Charles University in Prague, Faculty of Pharmacy in Hradec Kralove, Czech Republic
| | - Martina Ceckova
- Deparment of Pharmacology and Toxicology, Charles University in Prague, Faculty of Pharmacy in Hradec Kralove, Czech Republic
| | - Frantisek Staud
- Deparment of Pharmacology and Toxicology, Charles University in Prague, Faculty of Pharmacy in Hradec Kralove, Czech Republic
| | - Tomas Laho
- Department of Pharmacology, Charles University in Prague, Faculty of Medicine in Hradec Kralove, Czech Republic
| | - Stanislav Micuda
- Department of Pharmacology, Charles University in Prague, Faculty of Medicine in Hradec Kralove, Czech Republic.
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359
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Ruszkiewicz J, Albrecht J. Changes in the mitochondrial antioxidant systems in neurodegenerative diseases and acute brain disorders. Neurochem Int 2015; 88:66-72. [PMID: 25576182 DOI: 10.1016/j.neuint.2014.12.012] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 12/21/2014] [Accepted: 12/29/2014] [Indexed: 12/30/2022]
Abstract
Oxidative and nitrosative stress (ONS) contributes to the pathogenesis of most brain maladies, and the magnitude of ONS is related to the ability of cellular antioxidants to neutralize the accumulating reactive oxygen and nitrogen species (ROS/RNS). While the major ROS/RNS scavengers and regenerators of bio-oxidized molecules, superoxide dysmutases (SODs), glutathione (GSH), thioredoxin (Trx) and peroxiredoxin (Prx), are distributed in all cellular compartments. This review specifically focuses on the role of the systems operating in mitochondria. There is a growing consensus that the mitochondrial SOD isoform - SOD2 and GSH are critical for the cellular antioxidant defense. Variable changes of the expression or activities of one or more of the mitochondrial antioxidant systems have been documented in the brains derived from human patients and/or in animal models of neurodegenerative diseases (Alzheimer's disease, Parkinson's disease), cerebral ischemia, toxic brain cell damage associated with overexposure to mercury or excitotoxins, or hepatic encephalopathy. In many cases, ambiguity of the responses of the different antioxidant systems in one and the same disease needs to be more conclusively evaluated before the balance of the changes is viewed as beneficial or detrimental. Modulation of the mitochondrial antioxidant systems may in the future become a target of antioxidant therapy.
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Affiliation(s)
- Joanna Ruszkiewicz
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Jan Albrecht
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Sciences, 02-106 Warsaw, Poland.
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360
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Zhang J. Reduced Glutathione Promotes Implants Osseointegration in Rabbits with Diabetes Mellitus: An Experimental Study. J HARD TISSUE BIOL 2015. [DOI: 10.2485/jhtb.24.277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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361
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Pompella A, Corti A. Editorial: the changing faces of glutathione, a cellular protagonist. Front Pharmacol 2015. [PMID: 26029106 DOI: 10.3389/fphar.2015.00098/full] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023] Open
Affiliation(s)
- Alfonso Pompella
- Department of Translational Research NTMC, University of Pisa Pisa, Italy
| | - Alessandro Corti
- Department of Translational Research NTMC, University of Pisa Pisa, Italy
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362
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Hermann PM, Watson SN, Wildering WC. Phospholipase A2 - nexus of aging, oxidative stress, neuronal excitability, and functional decline of the aging nervous system? Insights from a snail model system of neuronal aging and age-associated memory impairment. Front Genet 2014; 5:419. [PMID: 25538730 PMCID: PMC4255604 DOI: 10.3389/fgene.2014.00419] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Accepted: 11/13/2014] [Indexed: 02/02/2023] Open
Abstract
The aging brain undergoes a range of changes varying from subtle structural and physiological changes causing only minor functional decline under healthy normal aging conditions, to severe cognitive or neurological impairment associated with extensive loss of neurons and circuits due to age-associated neurodegenerative disease conditions. Understanding how biological aging processes affect the brain and how they contribute to the onset and progress of age-associated neurodegenerative diseases is a core research goal in contemporary neuroscience. This review focuses on the idea that changes in intrinsic neuronal electrical excitability associated with (per)oxidation of membrane lipids and activation of phospholipase A2 (PLA2) enzymes are an important mechanism of learning and memory failure under normal aging conditions. Specifically, in the context of this special issue on the biology of cognitive aging we portray the opportunities offered by the identifiable neurons and behaviorally characterized neural circuits of the freshwater snail Lymnaea stagnalis in neuronal aging research and recapitulate recent insights indicating a key role of lipid peroxidation-induced PLA2 as instruments of aging, oxidative stress and inflammation in age-associated neuronal and memory impairment in this model system. The findings are discussed in view of accumulating evidence suggesting involvement of analogous mechanisms in the etiology of age-associated dysfunction and disease of the human and mammalian brain.
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Affiliation(s)
- Petra M Hermann
- Department of Biological Sciences, University of Calgary Calgary, AB, Canada ; Department of Physiology and Pharmacology, University of Calgary Calgary, AB, Canada
| | - Shawn N Watson
- Department of Biological Sciences, University of Calgary Calgary, AB, Canada
| | - Willem C Wildering
- Department of Biological Sciences, University of Calgary Calgary, AB, Canada ; Department of Physiology and Pharmacology, University of Calgary Calgary, AB, Canada ; Hotchkiss Brain Institute, University of Calgary Calgary, AB, Canada
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363
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Glutathione-Dependent Detoxification Processes in Astrocytes. Neurochem Res 2014; 40:2570-82. [PMID: 25428182 DOI: 10.1007/s11064-014-1481-1] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 11/10/2014] [Accepted: 11/15/2014] [Indexed: 01/17/2023]
Abstract
Astrocytes have a pivotal role in brain as partners of neurons in homeostatic and metabolic processes. Astrocytes also protect other types of brain cells against the toxicity of reactive oxygen species and are considered as first line of defence against the toxic potential of xenobiotics. A key component in many of the astrocytic detoxification processes is the tripeptide glutathione (GSH) which serves as electron donor in the GSH peroxidase-catalyzed reduction of peroxides. In addition, GSH is substrate in the detoxification of xenobiotics and endogenous compounds by GSH-S-transferases which generate GSH conjugates that are efficiently exported from the cells by multidrug resistance proteins. Moreover, GSH reacts with the reactive endogenous carbonyls methylglyoxal and formaldehyde to intermediates which are substrates of detoxifying enzymes. In this article we will review the current knowledge on the GSH metabolism of astrocytes with a special emphasis on GSH-dependent detoxification processes.
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364
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Mitochondrial cholesterol: mechanisms of import and effects on mitochondrial function. J Bioenerg Biomembr 2014; 48:137-51. [PMID: 25425472 DOI: 10.1007/s10863-014-9592-6] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 11/14/2014] [Indexed: 12/23/2022]
Abstract
Mitochondria require cholesterol for biogenesis and membrane maintenance, and for the synthesis of steroids, oxysterols and hepatic bile acids. Multiple pathways mediate the transport of cholesterol from different subcellular pools to mitochondria. In steroidogenic cells, the steroidogenic acute regulatory protein (StAR) interacts with a mitochondrial protein complex to mediate cholesterol delivery to the inner mitochondrial membrane for conversion to pregnenolone. In non-steroidogenic cells, several members of a protein family defined by the presence of a StAR-related lipid transfer (START) domain play key roles in the delivery of cholesterol to mitochondrial membranes. Subdomains of the endoplasmic reticulum (ER), termed mitochondria-associated ER membranes (MAM), form membrane contact sites with mitochondria and may contribute to the transport of ER cholesterol to mitochondria, either independently or in conjunction with lipid-transfer proteins. Model systems of mitochondria enriched with cholesterol in vitro and mitochondria isolated from cells with (patho)physiological mitochondrial cholesterol accumulation clearly demonstrate that mitochondrial cholesterol levels affect mitochondrial function. Increased mitochondrial cholesterol levels have been observed in several diseases, including cancer, ischemia, steatohepatitis and neurodegenerative diseases, and influence disease pathology. Hence, a deeper understanding of the mechanisms maintaining mitochondrial cholesterol homeostasis may reveal additional targets for therapeutic intervention. Here we give a brief overview of mitochondrial cholesterol import in steroidogenic cells, and then focus on cholesterol trafficking pathways that deliver cholesterol to mitochondrial membranes in non-steroidogenic cells. We also briefly discuss the consequences of increased mitochondrial cholesterol levels on mitochondrial function and their potential role in disease pathology.
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365
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Mailloux RJ, Willmore WG. S-glutathionylation reactions in mitochondrial function and disease. Front Cell Dev Biol 2014; 2:68. [PMID: 25453035 PMCID: PMC4233936 DOI: 10.3389/fcell.2014.00068] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 10/31/2014] [Indexed: 01/23/2023] Open
Abstract
Mitochondria are highly efficient energy-transforming organelles that convert energy stored in nutrients into ATP. The production of ATP by mitochondria is dependent on oxidation of nutrients and coupling of exergonic electron transfer reactions to the genesis of transmembrane electrochemical potential of protons. Electrons can also prematurely “spin-off” from prosthetic groups in Krebs cycle enzymes and respiratory complexes and univalently reduce di-oxygen to generate reactive oxygen species (ROS) superoxide (O2•−) and hydrogen peroxide (H2O2), important signaling molecules that can be toxic at high concentrations. Production of ATP and ROS are intimately linked by the respiratory chain and the genesis of one or the other inherently depends on the metabolic state of mitochondria. Various control mechanisms converge on mitochondria to adjust ATP and ROS output in response to changing cellular demands. One control mechanism that has gained a high amount of attention recently is S-glutathionylation, a redox sensitive covalent modification that involves formation of a disulfide bridge between glutathione and an available protein cysteine thiol. A number of S-glutathionylation targets have been identified in mitochondria. It has also been established that S-glutathionylation reactions in mitochondria are mediated by the thiol oxidoreductase glutaredoxin-2 (Grx2). In the following review, emerging knowledge on S-glutathionylation reactions and its importance in modulating mitochondrial ATP and ROS production will be discussed. Major focus will be placed on Complex I of the respiratory chain since (1) it is a target for reversible S-glutathionylation by Grx2 and (2) deregulation of Complex I S-glutathionylation is associated with development of various disease states particularly heart disease. Other mitochondrial enzymes and how their S-glutathionylation profile is affected in different disease states will also be discussed.
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Affiliation(s)
- Ryan J Mailloux
- Department of Biology, Faculty of Sciences, University of Ottawa Ottawa, ON, Canada
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Övey İS, Naziroğlu M. Homocysteine and cytosolic GSH depletion induce apoptosis and oxidative toxicity through cytosolic calcium overload in the hippocampus of aged mice: involvement of TRPM2 and TRPV1 channels. Neuroscience 2014; 284:225-233. [PMID: 25305668 DOI: 10.1016/j.neuroscience.2014.09.078] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 09/29/2014] [Accepted: 09/30/2014] [Indexed: 11/15/2022]
Abstract
Oxidative stress and apoptosis were induced in neuronal cultures by inhibition of glutathione (GSH) biosynthesis with d,l-buthionine-S,R-sulfoximine (BSO). Transient receptor potential melastatin 2 (TRPM2) and transient receptor potential vanilloid 1 (TRPV1) cation channels are gated by oxidative stress. The oxidant effects of homocysteine (Hcy) may induce activation of TRPV1 and TRPM2 channels in aged mice as a model of Alzheimer's disease (AD). We tested the effects of Hcy, BSO and GSH on oxidative stress, apoptosis and Ca2+ and influx via TRPM2 and TRPV1 channels in the hippocampus of mice. Native mice hippocampal neurons were divided into five groups as follows; control, Hcy, BSO, Hcy+BSO and Hcy+BSO+GSH groups. The neurons in TRPM2 and TRPV1 experiments were stimulated by hydrogen peroxide and capsaicin, respectively. BSO and Hcy incubations increased intracellular free Ca2+ concentrations, reactive oxygen species, apoptosis, mitochondrial depolarization, and levels of caspase 3 and 9. All of these increases were reduced by GSH treatments. Treatment with 2-aminoethoxydiphenyl borate (2-APB) and N-(p-amylcinnamoyl)anthranilic acid (ACA) as potent inhibitors of TRPM2, capsazepine as a potent inhibitor of TRPV1, verapamil+diltiazem (V+D) as inhibitors of the voltage-gated Ca2+ channels (VGCC) and MK-801 as a N-methyl-d-aspartate (NMDA) channel antagonist indicated that GSH depletion and Hcy elevation activated Ca2+ entry into the neurons through TRPM2, TRPV1, VGCC and NMDA channels. Inhibitor roles of 2-APB and capsazepine on the Ca2+ entry higher than in V+D and MK-801 antagonists. In conclusion, these findings support the idea that GSH depletion and Hcy elevation can have damaging effects on hippocampal neurons by perturbing calcium homeostasis, mainly through TRPM2 and TRPV1 channels. GSH treatment can partially reverse these effects.
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Affiliation(s)
- İ S Övey
- Department of Biophysics, Faculty of Medicine, University of Suleyman Demirel, Isparta, Turkey
| | - M Naziroğlu
- Department of Biophysics, Faculty of Medicine, University of Suleyman Demirel, Isparta, Turkey; Neuroscience Research Center, University of Suleyman Demirel, Isparta, Turkey.
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367
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Marí M, Morales A, Colell A, García-Ruiz C, Fernández-Checa JC. Mitochondrial cholesterol accumulation in alcoholic liver disease: Role of ASMase and endoplasmic reticulum stress. Redox Biol 2014; 3:100-8. [PMID: 25453982 PMCID: PMC4297930 DOI: 10.1016/j.redox.2014.09.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 09/21/2014] [Accepted: 09/23/2014] [Indexed: 02/08/2023] Open
Abstract
Alcoholic liver disease (ALD) is a major cause of chronic liver disease and a growing health concern in theworld. While the pathogenesis of ALD is poorly characterized key players identified in experimental models and patients, such as perturbations in mitochondrial structure and function, selective loss of antioxidant defense and susceptibility to inflammatory cytokines, contribute to ALD progression. Both oxidative stress and mitochondrial dysfunction compromise essential cellular functions and energy generation and hence are important pathogenic mechanisms of ALD. An important process mediating the mitochondrial disruption induced by alcohol intake is the trafficking of cholesterol to mitochondria, mediated by acid sphingomyelinase-induced endoplasmic reticulum stress, which contributes to increased cholesterol synthesis and StARD1upregulation. Mitochondrial cholesterol accumulation not only sensitizes to oxidative stress but it can contribute to the metabolic reprogramming in ALD, manifested by activation of the hypoxia inducible transcription factor 1 and stimulation of glycolysis and lactate secretion. Thus, a better understanding of the mechanisms underlying alcohol-mediated mitochondrial impairment and oxidative stress may lead to the identification of novel treatments for ALD. The present review briefly summarizes current knowledge on the cellular and molecular mechanisms contributing to alcohol-induced mitochondrial dysfunction and cholesterol accumulation and provides insights for potential therapeutic targets in ALD. Alcohol perturbs mitochondria function, which modulates ROS generation and alcohol metabolism. Alcohol stimulates mitochondrial cholesterol (mChol) accumulation. MChol accumulation impairs mitochondrial function and mediates alcohol-induced lipotoxicity. ASMase promotes mitochondrial dysfunction by stimulating mChol loading.
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Affiliation(s)
- Montserrat Marí
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB-CSIC), Consejo Superior Investigaciones Científicas (CSIC), IDIBAPS, Liver Unit-Hospital Clínic, CIBEREHD, 08036 Barcelona, Spain.
| | - Albert Morales
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB-CSIC), Consejo Superior Investigaciones Científicas (CSIC), IDIBAPS, Liver Unit-Hospital Clínic, CIBEREHD, 08036 Barcelona, Spain
| | - Anna Colell
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB-CSIC), Consejo Superior Investigaciones Científicas (CSIC), IDIBAPS, Liver Unit-Hospital Clínic, CIBEREHD, 08036 Barcelona, Spain
| | - Carmen García-Ruiz
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB-CSIC), Consejo Superior Investigaciones Científicas (CSIC), IDIBAPS, Liver Unit-Hospital Clínic, CIBEREHD, 08036 Barcelona, Spain
| | - Jose C Fernández-Checa
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB-CSIC), Consejo Superior Investigaciones Científicas (CSIC), IDIBAPS, Liver Unit-Hospital Clínic, CIBEREHD, 08036 Barcelona, Spain; Research Center for Alcoholic Liver and Pancreatic Diseases, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA.
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