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Shahabuddin F, Naseem S, Alam T, Khan AA, Khan F. Chronic aluminium chloride exposure induces redox imbalance, metabolic distress, DNA damage, and histopathologic alterations in Wistar rat liver. Toxicol Ind Health 2024; 40:581-595. [PMID: 39138847 DOI: 10.1177/07482337241269784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2024]
Abstract
Aluminium, a ubiquitous environmental toxicant, is distinguished for eliciting a broad range of physiological, biochemical, and behavioural alterations in laboratory animals and humans. The present work was conducted to study the functional and structural changes induced by aluminium in rat liver. Twenty five adult male Wistar rats (150-200 g) were randomly divided into five groups; control group and four Al-treated groups viz: Al 1 (25 mg AlCl3/kg b.wt), Al 2 (35 mg AlCl3/kg b.wt), Al 3 (45 mg AlCl3/kg b.wt), and Al 4 (55 mg AlCl3/kg b.wt). Rats in the aluminium-treated groups were administered AlCl3 for 30 days through oral gavage. Aluminium significantly increased the serum levels of liver function markers (ALT, AST, and ALP), phospholipids, and cholesterol. The activities of hepatocyte membrane (ALP, GGT, and LAP) and carbohydrate metabolic (G6P, F16BP, HK, LDH, MDH, ME, and G6PDH) enzymes were significantly altered by AlCl3 administration. Prolonged Al exposure induced oxidative stress in the liver, as evident by significant hepatocellular DNA damage, increased lipid peroxidation, and decreased non-enzymatic and enzymatic antioxidants. The toxic effects observed in this study were AlCl3 dose-dependent. Histopathological examination of liver sections revealed enlargement of sinusoidal spaces, derangement of the hepatic chord, loss of discrete hepatic cell boundaries, congestion of hepatic sinusoids, and degeneration of hepatocytes in Al-intoxicated rats. In conclusion, aluminium causes severe hepatotoxicity by inhibiting the hepatocyte membrane enzymes and disrupting the liver's energy metabolism and antioxidant defence.
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Affiliation(s)
- Farha Shahabuddin
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh, India
| | - Samina Naseem
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh, India
| | - Tauseef Alam
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh, India
| | - Aijaz Ahmed Khan
- Department of Anatomy, Faculty of Medicine, JN Medical College, Aligarh Muslim University, Aligarh, Uttar Pradesh, India
| | - Farah Khan
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh, India
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MacLean A, Legendre F, Appanna VD. The tricarboxylic acid (TCA) cycle: a malleable metabolic network to counter cellular stress. Crit Rev Biochem Mol Biol 2023; 58:81-97. [PMID: 37125817 DOI: 10.1080/10409238.2023.2201945] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The tricarboxylic acid (TCA) cycle is a primordial metabolic pathway that is conserved from bacteria to humans. Although this network is often viewed primarily as an energy producing engine fueling ATP synthesis via oxidative phosphorylation, mounting evidence reveals that this metabolic hub orchestrates a wide variety of pivotal biological processes. It plays an important part in combatting cellular stress by modulating NADH/NADPH homeostasis, scavenging ROS (reactive oxygen species), producing ATP by substrate-level phosphorylation, signaling and supplying metabolites to quell a range of cellular disruptions. This review elaborates on how the reprogramming of this network prompted by such abiotic stress as metal toxicity, oxidative tension, nutrient challenge and antibiotic insult is critical for countering these conditions in mostly microbial systems. The cross-talk between the stressors and the participants of TCA cycle that results in changes in metabolite and nucleotide concentrations aimed at combatting the abiotic challenge is presented. The fine-tuning of metabolites mediated by disparate enzymes associated with this metabolic hub is discussed. The modulation of enzymatic activities aimed at generating metabolic moieties dedicated to respond to the cellular perturbation is explained. This ancient metabolic network has to be recognized for its ability to execute a plethora of physiological functions beyond its well-established traditional roles.
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Affiliation(s)
- Alex MacLean
- School of Natural Sciences, Laurentian University, Sudbury, Canada
| | - Felix Legendre
- School of Natural Sciences, Laurentian University, Sudbury, Canada
| | - Vasu D Appanna
- School of Natural Sciences, Laurentian University, Sudbury, Canada
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Gaur A, Nayak P, Ghosh S, Sengupta T, Sakthivadivel V. Aluminum as a Possible Cause Toward Dyslipidemia. Indian J Occup Environ Med 2023; 27:112-119. [PMID: 37600652 PMCID: PMC10434801 DOI: 10.4103/ijoem.ijoem_349_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 03/24/2022] [Indexed: 08/22/2023] Open
Abstract
Aluminum, the third most abundant metal present in the earth's crust, is present almost in all daily commodities we use, and exposure to it is unavoidable. The interference of aluminum with various biochemical reactions in the body leads to detrimental health effects, out of which aluminum-induced neurodegeneration is widely studied. However, the effect of aluminum in causing dyslipidemia cannot be neglected. Dyslipidemia is a global health problem, which commences to the cosmic of non-communicable diseases. The interference of aluminum with various iron-dependent enzymatic activities in the tri-carboxylic acid cycle and electron transport chain results in decreased production of mitochondrial adenosine tri-phosphate. This ultimately contributes to oxidative stress and iron-mediated lipid peroxidation. This mitochondrial dysfunction along with modulation of α-ketoglutarate and L-carnitine perturbs lipid metabolism, leading to the atypical accumulation of lipids and dyslipidemia. Respiratory chain disruption because of the accumulation of reduced nicotinamide adenine di-nucleotide as a consequence of oxidative stress and the stimulatory effect of aluminum exposure on glycolysis causes many health issues including fat accumulation, obesity, and other hepatic disorders. One major factor contributing to dyslipidemia and enhanced pro-inflammatory responses is estrogen. Aluminum, being a metalloestrogen, modulates estrogen receptors, and in this world of industrialization and urbanization, we could corner down to metals, particularly aluminum, in the development of dyslipidemia. As per PRISMA guidelines, we did a literature search in four medical databases to give a holistic view of the possible link between aluminum exposure and various biochemical events leading to dyslipidemia.
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Affiliation(s)
- Archana Gaur
- Department of Physiology, All India Institute of Medical Sciences, Bibinagar, Hyderabad, Telangana, India
| | - Prasunpriya Nayak
- Department of Physiology, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India
| | - Sutirtha Ghosh
- Department of Physiology, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India
| | - Trina Sengupta
- Department of Physiology, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India
| | - Varatharajan Sakthivadivel
- Department of General Medicine, All India Institute of Medical Sciences, Bibinagar, Hyderabad, Telangana, India
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Aschner M, Skalny AV, Lu R, Santamaria A, Zhou JC, Ke T, Karganov MY, Tsatsakis A, Golokhvast KS, Bowman AB, Tinkov AA. The role of hypoxia-inducible factor 1 alpha (HIF-1α) modulation in heavy metal toxicity. Arch Toxicol 2023; 97:1299-1318. [PMID: 36933023 DOI: 10.1007/s00204-023-03483-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 03/02/2023] [Indexed: 03/19/2023]
Abstract
Hypoxia-inducible factor 1 (HIF-1) is an oxygen-sensing transcriptional regulator orchestrating a complex of adaptive cellular responses to hypoxia. Several studies have demonstrated that toxic metal exposure may also modulate HIF-1α signal transduction pathway, although the existing data are scarce. Therefore, the present review aims to summarize the existing data on the effects of toxic metals on HIF-1 signaling and the potential underlying mechanisms with a special focus on prooxidant effect of the metals. The particular effect of metals was shown to be dependent on cell type, varying from down- to up-regulation of HIF-1 pathway. Inhibition of HIF-1 signaling may contribute to impaired hypoxic tolerance and adaptation, thus promoting hypoxic damage in the cells. In contrast, its metal-induced activation may result in increased tolerance to hypoxia through increased angiogenesis, thus promoting tumor growth and contributing to carcinogenic effect of heavy metals. Up-regulation of HIF-1 signaling is mainly observed upon Cr, As, and Ni exposure, whereas Cd and Hg may both stimulate and inhibit HIF-1 pathway. The mechanisms underlying the influence of toxic metal exposure on HIF-1 signaling involve modulation of prolyl hydroxylases (PHD2) activity, as well as interference with other tightly related pathways including Nrf2, PI3K/Akt, NF-κB, and MAPK signaling. These effects are at least partially mediated by metal-induced ROS generation. Hypothetically, maintenance of adequate HIF-1 signaling upon toxic metal exposure through direct (PHD2 modulation) or indirect (antioxidant) mechanisms may provide an additional strategy for prevention of adverse effects of metal toxicity.
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Affiliation(s)
- Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Anatoly V Skalny
- IM Sechenov First Moscow State Medical University (Sechenov University), 119435, Moscow, Russia
| | - Rongzhu Lu
- Department of Preventive Medicine and Public Health Laboratory Science, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Abel Santamaria
- Laboratorio de Aminoácidos Excitadores/Laboratorio de Neurofarmacología Molecular y Nanotecnología, Instituto Nacional de Neurología y Neurocirugía, 14269, Mexico City, Mexico
| | - Ji-Chang Zhou
- School of Public Health (Shenzhen), Sun Yat-Sen University, Shenzhen, 518100, China
| | - Tao Ke
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | | | - Aristides Tsatsakis
- IM Sechenov First Moscow State Medical University (Sechenov University), 119435, Moscow, Russia.,Laboratory of Toxicology, Medical School, University of Crete, Voutes, 700 13, Heraklion, Crete, Greece
| | - Kirill S Golokhvast
- Siberian Federal Scientific Centre of Agrobiotechnologies of the Russian Academy of Sciences, Krasnoobsk, Russia
| | - Aaron B Bowman
- School of Health Sciences, Purdue University, West Lafayette, USA
| | - Alexey A Tinkov
- IM Sechenov First Moscow State Medical University (Sechenov University), 119435, Moscow, Russia. .,Laboratory of Ecobiomonitoring and Quality Control, Yaroslavl State University, 150003, Yaroslavl, Russia.
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Liang H, Xu P, Xu G, Zhang L, Huang D, Ren M, Zhang L. Histidine Deficiency Inhibits Intestinal Antioxidant Capacity and Induces Intestinal Endoplasmic-Reticulum Stress, Inflammatory Response, Apoptosis, and Necroptosis in Largemouth Bass ( Micropterus salmoides). Antioxidants (Basel) 2022; 11:2399. [PMID: 36552607 PMCID: PMC9774248 DOI: 10.3390/antiox11122399] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/12/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
This 56-day study aimed to evaluate the effects of histidine levels on intestinal antioxidant capacity and endoplasmic-reticulum stress (ERS) in largemouth bass (Micropterus salmoides). The initial weights of the largemouth bass were (12.33 ± 0.01) g. They were fed six graded levels of histidine: 0.71% (deficient group), 0.89%, 1.08%, 1.26%, 1.48%, and 1.67%. The results showed that histidine deficiency significantly suppressed the intestinal antioxidant enzyme activities, including SOD, CAT, GPx, and intestinal level of GSH, which was supported by significantly higher levels of intestinal MDA. Moreover, histidine deficiency significantly lowered the mRNA level of nrf2 and upregulated the mRNA level of keap1, which further lowered the mRNA levels of the downstream genes sod, cat, and gpx. Additionally, histidine-deficiency-induced intestinal ERS, which was characterized by activating the PEPK-signalling pathway and IRE1-signalling pathway, including increased core gene expression of pepk, grp78, eif2α, atf4, chopα, ire1, xbp1, traf2, ask1, and jnk1. Dietary histidine deficiency also induced apoptosis and necroptosis in the intestine by upregulating the expressions of proapoptotic genes, including caspase 3, caspase 8, caspase 9, and bax, and necroptosis-related genes, including mlkl and ripk3, while also lowering the mRNA level of the antiapoptotic gene bcl-2. Furthermore, histidine deficiency activated the NF-κB-signalling pathway to induce an inflammatory response, improving the mRNA levels of the proinflammatory factors tnf-α, hepcidin 1, cox2, cd80, and cd83 and lowering the mRNA levels of the anti-inflammatory factors tgf-β1 and ikbα. Similarly, dietary histidine deficiency significantly lowered the intestinal levels of the anti-inflammatory factors TGF-β and IL-10 and upregulated the intestinal levels of the proinflammatory factor TNF-α, showing a trend similar to the gene expression of inflammatory factors. However, dietary histidine deficiency inhibited only the level of C3, and no significant effects were observed for IgM, IgG, HSP70, or IFN-γ. Based on the MDA and T-SOD results, the appropriate dietary histidine requirements of juvenile largemouth bass were 1.32% of the diet (2.81% dietary protein) and 1.47% of the diet (3.13% dietary protein), respectively, as determined by quadratic regression analysis.
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Affiliation(s)
- Hualiang Liang
- Key Laboratory of Integrated Rice-Fish Farming Ecology, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
| | - Pao Xu
- Key Laboratory of Integrated Rice-Fish Farming Ecology, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
| | - Gangchun Xu
- Key Laboratory of Integrated Rice-Fish Farming Ecology, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
| | - Lin Zhang
- Key Laboratory of Integrated Rice-Fish Farming Ecology, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
| | - Dongyu Huang
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China
| | - Mingchun Ren
- Key Laboratory of Integrated Rice-Fish Farming Ecology, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
| | - Lu Zhang
- Healthy Aquaculture Key Laboratory of Sichuan Province, Tongwei Co., Ltd., Chengdu 610093, China
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Legendre F, MacLean A, Tharmalingam S, Appanna VD. A Metabolic Network Mediating the Cycling of Succinate, a Product of ROS Detoxification into α-Ketoglutarate, an Antioxidant. Antioxidants (Basel) 2022; 11:antiox11030560. [PMID: 35326210 PMCID: PMC8945261 DOI: 10.3390/antiox11030560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/07/2022] [Accepted: 03/14/2022] [Indexed: 11/16/2022] Open
Abstract
Sulfur is an essential element for life. However, the soil microbe Pseudomonas (P.) fluorescens can survive in a low sulfur environment. When cultured in a sulfur-deficient medium, the bacterium reprograms its metabolic pathways to produce α-ketoglutarate (KG) and regenerate this keto-acid from succinate, a by-product of ROS detoxification. Succinate semialdehyde dehydrogenase (SSADH) and KG decarboxylase (KGDC) work in partnership to synthesize KG. This process is further aided by the increased activity of the enzymes glutamate decarboxylase (GDC) and γ-amino-butyrate transaminase (GABAT). The pool of succinate semialdehyde (SSA) generated is further channeled towards the formation of the antioxidant. Spectrophotometric analyses, HPLC experiments and electrophoretic studies with intact cells and cell-free extracts (CFE) pointed to the metabolites (succinate, SSA, GABA) and enzymes (SSADH, GDC, KGDC) contributing to this KG-forming metabolic machinery. Real-time polymerase chain reaction (RT-qPCR) revealed significant increase in transcripts of such enzymes as SSADH, GDC and KGDC. The findings of this study highlight a novel pathway involving keto-acids in ROS scavenging. The cycling of succinate into KG provides an efficient means of combatting an oxidative environment. Considering the central role of KG in biological processes, this metabolic network may be operative in other living systems.
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Affiliation(s)
- Félix Legendre
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada; (F.L.); (A.M.); (S.T.)
| | - Alex MacLean
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada; (F.L.); (A.M.); (S.T.)
| | - Sujeenthar Tharmalingam
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada; (F.L.); (A.M.); (S.T.)
- Northern Ontario School of Medicine, Laurentian University, Sudbury, ON P3E 2C6, Canada
| | - Vasu D. Appanna
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada; (F.L.); (A.M.); (S.T.)
- Correspondence:
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7
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Elzakra N, Kim Y. HIF-1α Metabolic Pathways in Human Cancer. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1280:243-260. [PMID: 33791987 DOI: 10.1007/978-3-030-51652-9_17] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Oxygen is directly involved in many key pathophysiological processes. Oxygen deficiency, also known as hypoxia, could have adverse effects on mammalian cells, with ischemia in vital tissues being the most significant (Michiels C. Physiological and pathological responses to hypoxia. Am J Pathol 164(6): 1875-1882, 2004); therefore, timely adaptive responses to variations in oxygen availability are essential for cellular homeostasis and survival. The most critical molecular event in hypoxic response is the activation and stabilization of a transcriptional factor termed hypoxia-induced factor-1 (HIF-1) that is responsible for the upregulation of many downstream effector genes, collectively known as hypoxia-responsive genes. Multiple key biological pathways such as proliferation, energy metabolism, invasion, and metastasis are governed by these genes; thus, HIF-1-mediated pathways are equally pivotal in both physiology and pathology.As we gain knowledge on the molecular mechanisms underlying the regulation of HIF-1, a great focus has been placed on elucidating the cellular function of HIF-1, particularly the role of HIF-1 in cancer pathogenesis pathways such as proliferation, invasion, angiogenesis, and metastasis. In cancer, HIF-1 is directly involved in the shift of cancer tissues from oxidative phosphorylation to aerobic glycolysis, a phenomenon known as the Warburg effect. Although targeting HIF-1 as a cancer therapy seems like an extremely rational approach, owing to the complex network of its downstream effector genes, the development of specific HIF-1 inhibitors with fewer side effects and more specificity has not been achieved. Therefore, in this review, we provide a brief background about the function of HIF proteins in hypoxia response with a special emphasis on the unique role played by HIF-1α in cancer growth and invasiveness, in the hypoxia response context.
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Affiliation(s)
- Naseim Elzakra
- School of Dentistry, University of California Los Angeles, Los Angeles, CA, USA.
| | - Yong Kim
- School of Dentistry, University of California Los Angeles, Los Angeles, CA, USA. .,Laboratory of Stem Cell and Cancer Epigenetics, Center for Oral Oncology Research, UCLA School of Dentistry, Los Angeles, CA, USA. .,UCLA's Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA. .,Broad Stem Cell Research Institute, Los Angeles, CA, USA.
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Liu T, Gao Q, Yang B, Yin C, Chang J, Qian H, Xing G, Wang S, Li F, Zhang Y, Chen D, Cai J, Shi H, Aschner M, Appiah-Kubi K, He D, Lu R. Differential susceptibility of PC12 and BRL cells and the regulatory role of HIF-1α signaling pathway in response to acute methylmercury exposure under normoxia. Toxicol Lett 2020; 331:82-91. [PMID: 32461003 PMCID: PMC7366344 DOI: 10.1016/j.toxlet.2020.05.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 05/15/2020] [Accepted: 05/18/2020] [Indexed: 12/24/2022]
Abstract
Hypoxia-inducible factor 1 (HIF-1) is a critical nuclear transcription factor for adaptation to hypoxia; its regulatable subunit, HIF-1α, is a cytoprotective regulatory factor. We examined the effects of methylmercury (MeHg) in rat adrenal pheochromocytoma (PC12) cells and the rat hepatocyte cell line BRL. MeHg treatment led to time- and concentration-dependent toxicity in both lines with statistically significant cytotoxic effects at 5 μM and 10 μM in PC12 and BRL, respectively, at 0.5 h. HIF-1α protein levels were significantly decreased at 2.5 (PC12) and 5 (BRL) μM MeHg. Furthermore, MeHg reduced the protein levels of HIF-1α and its target genes (glucose transporter-1, vascular endothelial growth factor-A and erythropoietin). Overexpression of HIF-1α significantly attenuated MeHg-induced toxicity in both cell types. Notably, cobalt chloride, a pharmacological inducer of HIF-1α, significantly attenuated MeHg-induced toxicity in BRL but not PC12. In both cell lines, an inhibitor of prolyl hydroxylase, 3, 4-dihydroxybenzoic acid, and the proteasome inhibitor carbobenzoxy-L-leucyl-L-leucyl-L-leucinal(MG132), antagonized MeHg toxicity, while 2-methoxyestradiol, a HIF-1α inhibitor, significantly increased it. These data establish that: (a) neuron-like PC12 cells are more sensitive to MeHg than non-neuronal BRL cells; (b) HIF-1α plays a similar role in MeHg-induced toxicity in both cell lines; and (c) upregulation of HIF-1α offers general cytoprotection against MeHg toxicity in PC12 and BRL cell lines.
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Affiliation(s)
- Tingting Liu
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Qianqian Gao
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Bobo Yang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Changsheng Yin
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, China; Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Jie Chang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Hai Qian
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Guangwei Xing
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Suhua Wang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Fang Li
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Yubin Zhang
- Department of Occupational Health and Toxicology, School of Public Health, Fudan University, Shanghai 200032, China
| | - Da Chen
- School of Environment, Jinan University, Guangzhou, Guangdong 510632, China
| | - Jiyang Cai
- Department of Physiology, College of Medicine, University of Oklahoma Health Science Center, Lindsay, Oklahoma City, OK 73104, USA
| | - Haifeng Shi
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Kwaku Appiah-Kubi
- Department of Applied Biology, C. K. Tedam University of Technology and Applied Sciences, Navrongo, UK-0215-5321, Ghana
| | - Dawei He
- Center for Experimental Research, Kunshan Hospital Affiliated to Jiangsu University, Kunshan, Jiangsu 215130, China
| | - Rongzhu Lu
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China; Center for Experimental Research, Kunshan Hospital Affiliated to Jiangsu University, Kunshan, Jiangsu 215130, China.
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9
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Legendre F, MacLean A, Appanna VP, Appanna VD. Biochemical pathways to α-ketoglutarate, a multi-faceted metabolite. World J Microbiol Biotechnol 2020; 36:123. [PMID: 32686016 DOI: 10.1007/s11274-020-02900-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 07/13/2020] [Indexed: 11/26/2022]
Abstract
α-Ketoglutarate (AKG) also known as 2-oxoglutarate is an essential metabolite in virtually all organisms as it participates in a variety of biological processes including anti-oxidative defence, energy production, signalling modules, and genetic modification. This keto-acid also possesses immense commercial value as it is utilized as a nutritional supplement, a therapeutic agent, and a precursor to a variety of value-added products such as ethylene and heterocyclic compounds. Hence, the generation of KG in a sustainable and environmentally-neutral manner is a major ongoing research endeavour. In this mini-review, the enzymatic systems and the metabolic networks mediating the synthesis of AKG will be described. The importance of such enzymes as isocitrate dehydrogenase (ICDH), glutamate dehydrogenase (GDH), succinate semialdehyde dehydrogenase (SSADH) and transaminases that directly contribute to the formation of KG will be emphasized. The efficacy of microbial systems in providing an effective platform to generate this moiety and the molecular strategies involving genetic manipulation, abiotic stress and nutrient supplementation that result in the optimal production of AKG will be evaluated. Microbial systems and their components acting via the metabolic networks and the resident enzymes are well poised to provide effective biotechnological tools that can supply renewable AKG globally.
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Affiliation(s)
- F Legendre
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, P3E 2C6, Canada
| | - A MacLean
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, P3E 2C6, Canada
| | - V P Appanna
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, P3E 2C6, Canada
| | - V D Appanna
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, P3E 2C6, Canada.
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10
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Fusaric acid alters Akt and ampk signalling in c57bl/6 mice brain tissue. Food Chem Toxicol 2020; 138:111252. [DOI: 10.1016/j.fct.2020.111252] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 03/02/2020] [Accepted: 03/06/2020] [Indexed: 12/13/2022]
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11
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Chang J, Yang B, Zhou Y, Yin C, Liu T, Qian H, Xing G, Wang S, Li F, Zhang Y, Chen D, Aschner M, Lu R. Acute Methylmercury Exposure and the Hypoxia-Inducible Factor-1α Signaling Pathway under Normoxic Conditions in the Rat Brain and Astrocytes in Vitro. ENVIRONMENTAL HEALTH PERSPECTIVES 2019; 127:127006. [PMID: 31850806 PMCID: PMC6957278 DOI: 10.1289/ehp5139] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 11/07/2019] [Accepted: 11/18/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND As a ubiquitous environmental pollutant, methylmercury (MeHg) induces toxic effects in the nervous system, one of its main targets. However, the exact mechanisms of its neurotoxicity have not been fully elucidated. Hypoxia-inducible factor- 1 α (HIF- 1 α ), a transcription factor, plays a crucial role in adaptive and cytoprotective responses in cells and is involved in cell survival, proliferation, apoptosis, inflammation, angiogenesis, glucose metabolism, erythropoiesis, and other physiological activities. OBJECTIVES The aim of this study was to explore the role of HIF- 1 α in response to acute MeHg exposure in rat brain and primary cultured astrocytes to improve understanding of the mechanisms of MeHg-induced neurotoxicity and the development of effective neuroprotective strategies. METHODS Primary rat astrocytes were treated with MeHg (0 - 10 μ M ) for 0.5 h . Cell proliferation and cytotoxicity were assessed with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl diphenyltetrazolium bromide (MTT) assay and a lactate dehydrogenase (LDH) release assay, respectively. Reactive oxygen species (ROS) levels were analyzed to assess the level of oxidative stress using 2',7'-dichlorofluorescin diacetate (DCFH-DA) fluorescence. HIF- 1 α , and its downstream proteins, glucose transporter 1 (GLUT-1), erythropoietin (EPO), and vascular endothelial growth factor A (VEGF-A) were analyzed by means of Western blotting. Real-time PCR was used to detect the expression of HIF- 1 α mRNA. Pretreatment with protein synthesis inhibitor (CHX), proteasome inhibitor (MG132), or proline hydroxylase inhibitor (DHB) were applied to explore the possible mechanisms of HIF- 1 α inhibition by MeHg. To investigate the role of HIF- 1 α in MeHg-induced neurotoxicity, cobalt chloride (CoC l 2 ), 2-methoxyestradiol (2-MeOE2), small interfering RNA (siRNA) transfection and adenovirus overexpression were used. Pretreatment with N-acetyl-L-cysteine (NAC) and vitamin E (Trolox) were used to investigate the putative role of oxidative stress in MeHg-induced alterations in HIF- 1 α levels. The expression of HIF- 1 α and related downstream proteins was detected in adult rat brain exposed to MeHg (0 - 10 mg / kg ) for 0.5 h in vivo. RESULTS MeHg caused lower cell proliferation and higher cytotoxicity in primary rat astrocytes in a time- and concentration-dependent manner. In comparison with the control cells, exposure to 10 μ M MeHg for 0.5 h significantly inhibited the expression of astrocytic HIF- 1 α , and the downstream genes GLUT-1, EPO, and VEGF-A (p < 0.05 ), in the absence of a significant decrease in HIF- 1 α mRNA levels. When protein synthesis was inhibited by CHX, MeHg promoted the degradation rate of HIF- 1 α . MG132 and DHB significantly blocked the MeHg-induced decrease in HIF- 1 α expression (p < 0.05 ). Overexpression of HIF- 1 α significantly attenuated the decline in MeHg-induced cell proliferation, whereas the inhibition of HIF- 1 α significantly increased the decline in cell proliferation (p < 0.05 ). NAC and Trolox, two established antioxidants, reversed the MeHg-induced decline in HIF- 1 α protein levels and the decrease in cell proliferation (p < 0.05 ). MeHg suppressed the expression of HIF- 1 α and related downstream target proteins in adult rat brain. DISCUSSION MeHg induced a significant reduction in HIF- 1 α protein by activating proline hydroxylase (PHD) and the ubiquitin proteasome system (UPS) in primary rat astrocytes. Additionally, ROS scavenging by antioxidants played a neuroprotective role via increasing HIF- 1 α expression in response to MeHg toxicity. Moreover, we established that up-regulation of HIF- 1 α might serve to mitigate the acute toxicity of MeHg in astrocytes, affording a novel therapeutic target for future exploration. https://doi.org/10.1289/EHP5139.
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Affiliation(s)
- Jie Chang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Bobo Yang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Yun Zhou
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Changsheng Yin
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Tingting Liu
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Hai Qian
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Guangwei Xing
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Suhua Wang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Fang Li
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Yubin Zhang
- Department of Occupational Health and Toxicology, School of Public Health, Fudan University, Shanghai, China
| | - Da Chen
- School of Environment, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, China
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Rongzhu Lu
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
- Center for Experimental Research, Kunshan Hospital Affiliated to Jiangsu University, Kunshan, China
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12
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Shimizu K, Matsuoka Y. Redox rebalance against genetic perturbations and modulation of central carbon metabolism by the oxidative stress regulation. Biotechnol Adv 2019; 37:107441. [PMID: 31472206 DOI: 10.1016/j.biotechadv.2019.107441] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 08/04/2019] [Accepted: 08/23/2019] [Indexed: 12/11/2022]
Abstract
The micro-aerophilic organisms and aerobes as well as yeast and higher organisms have evolved to gain energy through respiration (via oxidative phosphorylation), thereby enabling them to grow much faster than anaerobes. However, during respiration, reactive oxygen species (ROSs) are inherently (inevitably) generated, and threaten the cell's survival. Therefore, living organisms (or cells) must furnish the potent defense systems to keep such ROSs at harmless level, where the cofactor balance plays crucial roles. Namely, NADH is the source of energy generation (catabolism) in the respiratory chain reactions, through which ROSs are generated, while NADPH plays important roles not only for the cell synthesis (anabolism) but also for detoxifying ROSs. Therefore, the cell must rebalance the redox ratio by modulating the fluxes of the central carbon metabolism (CCM) by regulating the multi-level regulation machinery upon genetic perturbations and the change in the growth conditions. Here, we discuss about how aerobes accomplish such cofactor homeostasis against redox perturbations. In particular, we consider how single-gene mutants (including pgi, pfk, zwf, gnd and pyk mutants) modulate their metabolisms in relation to cofactor rebalance (and also by adaptive laboratory evolution). We also discuss about how the overproduction of NADPH (by the pathway gene mutation) can be utilized for the efficient production of useful value-added chemicals such as medicinal compounds, polyhydroxyalkanoates, and amino acids, all of which require NADPH in their synthetic pathways. We then discuss about the metabolic responses against oxidative stress, where αketoacids play important roles not only for the coordination between catabolism and anabolism, but also for detoxifying ROSs by non-enzymatic reactions, as well as for reducing the production of ROSs by repressing the activities of the TCA cycle and respiration (via carbon catabolite repression). Thus, we discuss about the mechanisms (basic strategies) that modulate the metabolism from respiration to respiro-fermentative metabolism causing overflow, based on the role of Pyk activity, affecting the NADPH production at the oxidative pentose phosphate (PP) pathway, and the roles of αketoacids for the change in the source of energy generation from the oxidative phosphorylation to the substrate level phosphorylation.
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Affiliation(s)
- Kazuyuki Shimizu
- Kyushu institute of Technology, Iizuka, Fukuoka 820-8502, Japan; Institute of Advanced Biosciences, Keio university, Tsuruoka, Yamagata 997-0017, Japan.
| | - Yu Matsuoka
- Kyushu institute of Technology, Iizuka, Fukuoka 820-8502, Japan.
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Bayliak MM, Lylyk MP, Gospodaryov DV, Kotsyubynsky VO, Butenko NV, Storey KB, Lushchak VI. Protective effects of alpha-ketoglutarate against aluminum toxicity in Drosophila melanogaster. Comp Biochem Physiol C Toxicol Pharmacol 2019; 217:41-53. [PMID: 30508642 DOI: 10.1016/j.cbpc.2018.11.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 11/26/2018] [Accepted: 11/28/2018] [Indexed: 01/16/2023]
Abstract
In recent years, Drosophila melanogaster has emerged as a model for studies on aluminum toxicity. The current study aimed to disclose the mechanisms of aluminum toxicity in D. melanogaster at larval and adult stages and examined the potential protective effects of dietary alpha-ketoglutarate (AKG). Flies were reared on food containing 10 mM AlCl3, 10 mM AKG or both additives. Rearing on an AlCl3-containing diet induced behavioral defects, and decreased fecundity and long-term survival of female flies. The addition of dietary AKG did not ameliorate locomotor and taste behavior defects or the higher sensitivity to oxidative stress, but improved heat stress resistance, egg-laying capability and survival of females treated with AlCl3. Metabolic effects of AlCl3 exposure on flies included an imbalance of metal content, decreased glucose levels, increased free iron and storage triacylglyceride (TAG) levels, mitochondria dysfunction, and the development of oxidative stress. Dietary AKG did not prevent AlCl3 effects on glucose and TAG, but improved metal homeostasis, inhibited the increase in free Fe and restored the functional activity of iron-containing enzymes such as aconitase. In addition, AKG decreased the intensity of oxidative stress seen in AlCl3-reared adult flies, probably due to inhibition of iron mobilization. The results show that AKG is not a full antidote against Al toxicity but is able to relieve multiple metabolic effects of high aluminum. Furthermore, the modulating ability of AKG can clearly be helpful in exploring the molecular mechanisms of Al toxicity.
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Affiliation(s)
- Maria M Bayliak
- Department of Biochemistry and Biotechnology, Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., Ivano-Frankivsk 76018, Ukraine.
| | - Maria P Lylyk
- Department of Biochemistry and Biotechnology, Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., Ivano-Frankivsk 76018, Ukraine
| | - Dmytro V Gospodaryov
- Department of Biochemistry and Biotechnology, Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., Ivano-Frankivsk 76018, Ukraine.
| | - Volodymyr O Kotsyubynsky
- Department of Materials Science and Advanced Technologies, Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., Ivano-Frankivsk 76018, Ukraine
| | - Nataliia V Butenko
- Department of Biochemistry and Biotechnology, Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., Ivano-Frankivsk 76018, Ukraine
| | - Kenneth B Storey
- Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - Volodymyr I Lushchak
- Department of Biochemistry and Biotechnology, Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., Ivano-Frankivsk 76018, Ukraine.
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van Niekerk G, Mabin T, Engelbrecht AM. Anti-inflammatory mechanisms of cannabinoids: an immunometabolic perspective. Inflammopharmacology 2019; 27:39-46. [PMID: 30610735 DOI: 10.1007/s10787-018-00560-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 12/29/2018] [Indexed: 12/14/2022]
Abstract
A number of studies have implicated cannabinoids as potent anti-inflammatory mediators. However, the exact mechanism by which cannabinoids exert these effects remains to be fully explained. The recent resurgence in interest regarding the metabolic adaptations undergone by activated immune cells has highlighted the intricate connection between metabolism and an inflammatory phenotype. In this regard, evidence suggests that cannabinoids may alter cell metabolism by increasing AMPK activity. In turn, emerging evidence suggests that the activation of AMPK by cannabinoids may mediate an anti-inflammatory effect through a range of processes. First, AMPK may promote oxidative metabolism, which have been shown to play a central role in immune cell polarisation towards a tolerogenic phenotype. AMPK activation may also attenuate anabolic processes which in turn may antagonise immune cell function. Furthermore, AMPK activity promotes the induction of autophagy, which in turn may promote anti-inflammatory effects through various well-described processes. Taken together, these observations implicate cannabinoids to mediate part of their anti-inflammatory effects through alterations in immune cell metabolism and the induction of autophagy.
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Affiliation(s)
- G van Niekerk
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, South Africa.
| | - T Mabin
- Department of Medicine, Cardiology Division, University of Cape Town, Cape Town, South Africa
| | - A-M Engelbrecht
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, South Africa
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15
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Zhao C, Zhang C, Xing Z, Ahmad Z, Li JS, Chang MW. Pharmacological effects of natural Ganoderma and its extracts on neurological diseases: A comprehensive review. Int J Biol Macromol 2019; 121:1160-1178. [DOI: 10.1016/j.ijbiomac.2018.10.076] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 10/06/2018] [Accepted: 10/14/2018] [Indexed: 01/13/2023]
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16
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Tharmalingam S, Alhasawi A, Appanna VP, Lemire J, Appanna VD. Reactive nitrogen species (RNS)-resistant microbes: adaptation and medical implications. Biol Chem 2017. [PMID: 28622140 DOI: 10.1515/hsz-2017-0152] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Nitrosative stress results from an increase in reactive nitrogen species (RNS) within the cell. Though the RNS - nitric oxide (·NO) and peroxynitrite (ONOO-) - play pivotal physiological roles, at elevated concentrations, these moieties can be poisonous to both prokaryotic and eukaryotic cells alike due to their capacity to disrupt a variety of essential biological processes. Numerous microbes are known to adapt to nitrosative stress by elaborating intricate strategies aimed at neutralizing RNS. In this review, we will discuss both the enzymatic systems dedicated to the elimination of RNS as well as the metabolic networks that are tailored to generate RNS-detoxifying metabolites - α-keto-acids. The latter has been demonstrated to nullify RNS via non-enzymatic decarboxylation resulting in the production of a carboxylic acid, many of which are potent signaling molecules. Furthermore, as aerobic energy production is severely impeded during nitrosative stress, alternative ATP-generating modules will be explored. To that end, a holistic understanding of the molecular adaptation to nitrosative stress, reinforces the notion that neutralization of toxicants necessitates significant metabolic reconfiguration to facilitate cell survival. As the alarming rise in antimicrobial resistant pathogens continues unabated, this review will also discuss the potential for developing therapies that target the alternative ATP-generating machinery of bacteria.
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17
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Morris G, Puri BK, Frye RE. The putative role of environmental aluminium in the development of chronic neuropathology in adults and children. How strong is the evidence and what could be the mechanisms involved? Metab Brain Dis 2017; 32:1335-1355. [PMID: 28752219 PMCID: PMC5596046 DOI: 10.1007/s11011-017-0077-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Accepted: 07/19/2017] [Indexed: 02/06/2023]
Abstract
The conceptualisation of autistic spectrum disorder and Alzheimer's disease has undergone something of a paradigm shift in recent years and rather than being viewed as single illnesses with a unitary pathogenesis and pathophysiology they are increasingly considered to be heterogeneous syndromes with a complex multifactorial aetiopathogenesis, involving a highly complex and diverse combination of genetic, epigenetic and environmental factors. One such environmental factor implicated as a potential cause in both syndromes is aluminium, as an element or as part of a salt, received, for example, in oral form or as an adjuvant. Such administration has the potential to induce pathology via several routes such as provoking dysfunction and/or activation of glial cells which play an indispensable role in the regulation of central nervous system homeostasis and neurodevelopment. Other routes include the generation of oxidative stress, depletion of reduced glutathione, direct and indirect reductions in mitochondrial performance and integrity, and increasing the production of proinflammatory cytokines in both the brain and peripherally. The mechanisms whereby environmental aluminium could contribute to the development of the highly specific pattern of neuropathology seen in Alzheimer's disease are described. Also detailed are several mechanisms whereby significant quantities of aluminium introduced via immunisation could produce chronic neuropathology in genetically susceptible children. Accordingly, it is recommended that the use of aluminium salts in immunisations should be discontinued and that adults should take steps to minimise their exposure to environmental aluminium.
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Affiliation(s)
- Gerwyn Morris
- Tir Na Nog, Bryn Road seaside 87, Llanelli, Wales, SA15 2LW, UK
| | - Basant K Puri
- Department of Medicine, Imperial College London, Hammersmith Hospital, London, England, W12 0HS, UK.
| | - Richard E Frye
- College of Medicine, Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital Research Institute, Little Rock, AR, 72202, USA
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18
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Mitochondrial pathway is involved in the protective effects of alpha-ketoglutarate on hydrogen peroxide induced damage to intestinal cells. Oncotarget 2017; 8:74820-74835. [PMID: 29088826 PMCID: PMC5650381 DOI: 10.18632/oncotarget.20426] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 06/19/2017] [Indexed: 12/21/2022] Open
Abstract
Alpha-ketoglutarate, a key intermediate in the Krebs cycle, has been reported to benefit intestinal health. We tested whether alpha-ketoglutarate can protect intestinal cells against hydrogen peroxide induced damage and aimed to reveal the underlying mechanism. Intestinal porcine epithelial cell line J2 were cultured in Dulbecco’s Modified Eagle Medium-High glucose with or without alpha-ketoglutarate and hydrogen peroxide. Cell viability, proliferation, mitochondrial respiration, mitochondrial membrane potential, antioxidant function, apoptosis and mitochondrial-dependent apoptotic pathways were determined. Our experiments demonstrated that, first, exposure to 100μM hydrogen peroxide decreased cell viability, DNA synthesis, mitochondrial respiration and antioxidant function, and increased apoptosis. Second, 2mM alpha-ketoglutarate addition attenuated hydrogen peroxide-induced cell cycle arrest, and improved cell viability, DNA synthesis, mitochondrial respiration and antioxidant function. Third, alpha-ketoglutarate enhanced tricarboxylic acid cycle activity, mitochondrial respiration, and decrease the intracellular content of reactive oxygen species. Finally, alpha-ketoglutarate stabilized the mitochondrial membrane potential, increased the ratio of Bcl-2/Bax, decreased the release of cytochrome c and activation of caspase-3, thereby prevented cell apoptosis. Altogether, we proposed that alpha-ketoglutarate protects intestinal cells against hydrogen peroxide-induced damage partly via mitochondria dependent pathway.
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19
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Lemire J, Alhasawi A, Appanna VP, Tharmalingam S, Appanna VD. Metabolic defence against oxidative stress: the road less travelled so far. J Appl Microbiol 2017; 123:798-809. [PMID: 28609580 DOI: 10.1111/jam.13509] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 05/30/2017] [Accepted: 06/05/2017] [Indexed: 12/28/2022]
Abstract
Bacteria have survived, and many have thrived, since antiquity in the presence of the highly-reactive chalcogen-oxygen (O2 ). They are known to evoke intricate strategies to defend themselves from the reactive by-products of oxygen-reactive oxygen species (ROS). Many of these detoxifying mechanisms have been extensively characterized; superoxide dismutase, catalases, alkyl hydroperoxide reductase and the glutathione (GSH)-cycling system are responsible for neutralizing specific ROS. Meanwhile, a pool of NADPH-the reductive engine of many ROS-combating enzymes-is maintained by metabolic enzymes including, but not exclusively, glucose-6 phosphate dehydrogenase (G6PDH) and NADP-dependent isocitrate dehydrogenase (ICDH-NADP). So, it is not surprising that evidence continues to emerge demonstrating the pivotal role metabolism plays in mitigating ROS toxicity. Stemming from its ability to concurrently decrease the production of the pro-oxidative metabolite, NADH, while augmenting the antioxidative metabolite, NADPH, metabolism is the fulcrum of cellular redox potential. In this review, we will discuss the mounting evidence positioning metabolism and metabolic shifts observed during oxidative stress, as critical strategies microbes utilize to thrive in environments that are rife with ROS. The contribution of ketoacids-moieties capable of non-enzymatic decarboxylation in the presence of oxidants-as ROS scavengers will be elaborated alongside the metabolic pathways responsible for their homeostases. Further, the signalling role of the carboxylic acids generated following the ketoacid-mediated detoxification of the ROS will be commented on within the context of oxidative stress.
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Affiliation(s)
- J Lemire
- The Biofilm Research Group, The Department of Biological Sciences, The University of Calgary, Calgary, AB, Canada
| | - A Alhasawi
- Faculty of Science & Engineering, Laurentian University, Sudbury, ON, Canada
| | - V P Appanna
- Faculty of Science & Engineering, Laurentian University, Sudbury, ON, Canada
| | - S Tharmalingam
- Faculty of Science & Engineering, Laurentian University, Sudbury, ON, Canada
| | - V D Appanna
- Faculty of Science & Engineering, Laurentian University, Sudbury, ON, Canada
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20
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Guo S, Duan R, Wang L, Hou Y, Tan L, Cheng Q, Liao M, Ding B. Dietary α-ketoglutarate supplementation improves hepatic and intestinal energy status and anti-oxidative capacity of Cherry Valley ducks. Anim Sci J 2017; 88:1753-1762. [PMID: 28594103 DOI: 10.1111/asj.12824] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 03/21/2017] [Indexed: 12/25/2022]
Abstract
α-Ketoglutarate (AKG) is an extensively used dietary supplement in human and animal nutrition. The aim of the present study was to investigate effects of dietary AKG supplementation on the energy status and anti-oxidative capacity in liver and intestinal mucosa of Cherry Valley ducks. A total of 80 1-day-old ducks were randomly assigned into four groups, in which ducks were fed basal diets supplemented with 0% (control), 0.5%, 1.0% and 1.5% AKG, respectively. Graded doses of AKG supplementation linearly decreased the ratio of adenosine monophosphate (AMP) to adenosine triphosphate (ATP) in the liver, but increased ATP content and adenylate energy charge (AEC) in a quadratic and linear manner, respectively (P < 0.05). Increasing dietary AKG supplemental levels produced linear positive responses in ATP content and AEC, and negative responses in AMP concentration, the ratio of AMP to ATP and total adenine nucleotide in the ileal mucosa (P < 0.05). All levels of dietary AKG reduced the production of jejunal hydrogen peroxide and hepatic malondialdehyde (P < 0.05). Hepatic and ileal messenger RNA expression of AMP kinase α-1 and hypoxia-inducible factor-1α were linearly up-regulated as dietary AKG supplemental levels increased (P < 0.05). In conclusion, dietary AKG supplementation linearly or quadratically enhanced hepatic and intestinal energy storage and anti-oxidative capacity of Cherry Valley ducks.
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Affiliation(s)
- Shuangshuang Guo
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan, China
| | - Rui Duan
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan, China
| | - Lei Wang
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan, China
| | - Yongqing Hou
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan, China
| | - Linglin Tan
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan, China
| | - Qiang Cheng
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan, China
| | - Man Liao
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan, China
| | - Binying Ding
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan, China
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Abstract
Alzheimer's disease (AD) is a degenerative brain disease and the most common cause of dementia. AD is characterized by the extracellular amyloid beta (Aβ) plaques and intraneuronal deposits of neurofibrillary tangles (NFTs). Recently, as aging has become a familiar phenomenon around the world, patients with AD are increasing in number. Thus, many researchers are working toward finding effective therapeutics for AD focused on Aβ hypothesis, although there has been no success yet. In this review paper, we suggest that AD is a metabolic disease and that we should focus on metabolites that are affected by metabolic alterations to find effective therapeutics for AD. Aging is associated with not only AD but also obesity and type 2 diabetes (T2DM). AD, obesity, and T2DM share demographic profiles, risk factors, and clinical and biochemical features in common. Considering AD as a kind of metabolic disease, we suggest insulin, adiponectin, and antioxidants as mechanistic links among these diseases and targets for AD therapeutics. Patients with AD show reduced insulin signal transductions in the brain, and intranasal injection of insulin has been found to have an effect on AD treatment. In addition, adiponectin is decreased in the patients with obesity and T2DM. This reduction induces metabolic dysfunction both in the body and the brain, leading to AD pathogenesis. Oxidative stress is known to be induced by Aβ and NFTs, and we suggest that oxidative stress caused by metabolic alterations in the body induce brain metabolic alterations, resulting in AD.
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Affiliation(s)
- Somang Kang
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Korea
- BK21 Plus Project for Medical Sciences and Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Yong Ho Lee
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Jong Eun Lee
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Korea
- BK21 Plus Project for Medical Sciences and Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea. jelee@yuhs
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Aldarini N, Alhasawi AA, Thomas SC, Appanna VD. The role of glutamine synthetase in energy production and glutamine metabolism during oxidative stress. Antonie van Leeuwenhoek 2017; 110:629-639. [PMID: 28097538 DOI: 10.1007/s10482-017-0829-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 01/05/2017] [Indexed: 12/27/2022]
Abstract
Oxidative stress is known to severely impede aerobic adenosine triphosphate (ATP) synthesis. However, the metabolically-versatile Pseudomonas fluorescens survives this challenge by invoking alternative ATP-generating networks. When grown in a medium with glutamine as the sole organic nutrient in the presence of H2O2, the microbe utilizes glutamine synthetase (GS) to modulate its energy budget. The activity of this enzyme that mediates the release of energy stored in glutamine was sharply increased in the stressed cells compared to the controls. The enhanced activities of such enzymes as acetate kinase, adenylate kinase and nucleotide diphosphate kinase ensured the efficacy of this ATP producing-machine by transferring the high energy phosphate. The elevated amounts of phosphoenol pyruvate carboxylase and pyruvate orthophosphate dikinase recorded in the H2O2 exposed cells provided another route to ATP independent of the reduction of O2. This is the first demonstration of a metabolic pathway involving GS dedicated to ATP synthesis. The phospho-transfer network that is pivotal to the survival of the microorganism under oxidative stress may reveal therapeutic targets against infectious microbes reliant on glutamine for their proliferation.
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Affiliation(s)
- Nohaiah Aldarini
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, P3E 2C6, Canada
| | - Azhar A Alhasawi
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, P3E 2C6, Canada
| | - Sean C Thomas
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, P3E 2C6, Canada
| | - Vasu D Appanna
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, P3E 2C6, Canada.
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Appanna VP, Alhasawi AA, Auger C, Thomas SC, Appanna VD. Phospho-transfer networks and ATP homeostasis in response to an ineffective electron transport chain in Pseudomonas fluorescens. Arch Biochem Biophys 2016; 606:26-33. [PMID: 27431058 DOI: 10.1016/j.abb.2016.07.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 07/04/2016] [Accepted: 07/14/2016] [Indexed: 02/07/2023]
Abstract
Although oxidative stress is known to impede the tricarboxylic acid (TCA) cycle and oxidative phosphorylation, the nutritionally-versatile microbe, Pseudomonas fluorescens has been shown to proliferate in the presence of hydrogen peroxide (H2O2) and nitrosative stress. In this study we demonstrate the phospho-transfer system that enables this organism to generate ATP was similar irrespective of the carbon source utilized. Despite the diminished activities of enzymes involved in the TCA cycle and in the electron transport chain (ETC), the ATP levels did not appear to be significantly affected in the stressed cells. Phospho-transfer networks mediated by acetate kinase (ACK), adenylate kinase (AK), and nucleoside diphosphate kinase (NDPK) are involved in maintaining ATP homeostasis in the oxidatively-challenged cells. This phospho-relay machinery orchestrated by substrate-level phosphorylation is aided by the up-regulation in the activities of such enzymes like phosphoenolpyruvate carboxylase (PEPC), pyruvate orthophosphate dikinase (PPDK), and phosphoenolpyruvate synthase (PEPS). The enhanced production of phosphoenolpyruvate (PEP) and pyruvate further fuel the synthesis of ATP. Taken together, this metabolic reconfiguration enables the organism to fulfill its ATP need in an O2-independent manner by utilizing an intricate phospho-wire module aimed at maximizing the energy potential of PEP with the participation of AMP.
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Affiliation(s)
- V P Appanna
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON P3E 2C6, Canada
| | - A A Alhasawi
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON P3E 2C6, Canada
| | - C Auger
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON P3E 2C6, Canada
| | - S C Thomas
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON P3E 2C6, Canada
| | - V D Appanna
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON P3E 2C6, Canada.
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A. Alhasawi A, D. Appanna V. Manganese orchestrates a metabolic shift leading to the increased bioconversion of glycerol into α-ketoglutarate. AIMS BIOENGINEERING 2016. [DOI: 10.3934/bioeng.2017.1.12] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Thomas SC, Alhasawi A, Auger C, Omri A, Appanna VD. The role of formate in combatting oxidative stress. Antonie van Leeuwenhoek 2015; 109:263-71. [PMID: 26626058 DOI: 10.1007/s10482-015-0629-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 11/28/2015] [Indexed: 01/14/2023]
Abstract
The interaction of keto-acids with reactive oxygen species (ROS) is known to produce the corresponding carboxylic acid with the concomitant formation of CO2. Formate is liberated when the keto-acid glyoxylate neutralizes ROS. Here we report on how formate is involved in combating oxidative stress in the nutritionally-versatile Pseudomonas fluorescens. When the microbe was subjected to hydrogen peroxide (H2O2), the levels of formate were 8 and two-fold higher in the spent fluid and the soluble cell-free extracts obtained in the stressed cultures compared to the controls respectively. Formate was subsequently utilized as a reducing force to generate NADPH and succinate. The former is mediated by formate dehydrogenase (FDH-NADP), whose activity was enhanced in the stressed cells. Fumarate reductase that catalyzes the conversion of fumarate into succinate was also markedly increased in the stressed cells. These enzymes were modulated by H2O2. While the stressed whole cells produced copious amounts of formate in the presence of glycine, the cell-free extracts synthesized ATP and succinate from formate. Although the exact role of formate in anti-oxidative defence has to await further investigation, the data in this report suggest that this carboxylic acid may be a potent reductive force against oxidative stress.
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Affiliation(s)
- Sean C Thomas
- Faculty of Science, Engineering and Architecture, Laurentian University, Sudbury, ON, P3E 2C6, Canada
| | - Azhar Alhasawi
- Faculty of Science, Engineering and Architecture, Laurentian University, Sudbury, ON, P3E 2C6, Canada
| | - Christopher Auger
- Faculty of Science, Engineering and Architecture, Laurentian University, Sudbury, ON, P3E 2C6, Canada
| | - Abdelwahab Omri
- Faculty of Science, Engineering and Architecture, Laurentian University, Sudbury, ON, P3E 2C6, Canada
| | - Vasu D Appanna
- Faculty of Science, Engineering and Architecture, Laurentian University, Sudbury, ON, P3E 2C6, Canada.
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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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Thomas SC, Alhasawi A, Appanna VP, Auger C, Appanna VD. Brain metabolism and Alzheimer's disease: the prospect of a metabolite-based therapy. J Nutr Health Aging 2015; 19:58-63. [PMID: 25560817 DOI: 10.1007/s12603-014-0511-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The brain is one of the most energy-demanding organs in the body. It has evolved intricate metabolic networks to fulfill this need and utilizes a variety of substrates to generate ATP, the universal energy currency. Any disruption in the supply of energy results in various abnormalities including Alzheimer's disease (AD), a condition with markedly diminished cognitive ability. Astrocytes are an important participant in maintaining the cerebral ATP budget. However, under oxidative stress induced by numerous factors including aluminum toxicity, the ability of astroctyes to generate ATP is impaired due to dysfunctional mitochondria. This leads to globular, glycolytic, lipogenic and ATP-deficient astrocytes, cerebral characteristics common in AD patients. The reversal of these perturbations by such natural metabolites as pyruvate, α-ketoglutarate, acetoacetate and L-carnitine provides valuable therapeutic cues against AD.
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Affiliation(s)
- S C Thomas
- Vasu D. Appanna, Faculty of Science and Engineering, Laurentian University, Sudbury, Ontario, P3E 2C6, Canada. Phone: (705) 675-1151, ext. 2112, Fax: (705) 675-4844. E-mail:
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Lin CY, Hsiao WC, Huang CJ, Kao CF, Hsu GSW. Heme oxygenase-1 induction by the ROS–JNK pathway plays a role in aluminum-induced anemia. J Inorg Biochem 2013; 128:221-8. [DOI: 10.1016/j.jinorgbio.2013.07.026] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 07/16/2013] [Accepted: 07/16/2013] [Indexed: 01/16/2023]
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Han S, Lemire J, Appanna VP, Auger C, Castonguay Z, Appanna VD. How aluminum, an intracellular ROS generator promotes hepatic and neurological diseases: the metabolic tale. Cell Biol Toxicol 2013; 29:75-84. [PMID: 23463459 DOI: 10.1007/s10565-013-9239-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 02/04/2013] [Indexed: 01/10/2023]
Abstract
Metal pollutants are a global health risk due to their ability to contribute to a variety of diseases. Aluminum (Al), a ubiquitous environmental contaminant is implicated in anemia, osteomalacia, hepatic disorder, and neurological disorder. In this review, we outline how this intracellular generator of reactive oxygen species (ROS) triggers a metabolic shift towards lipogenesis in astrocytes and hepatocytes. This Al-evoked phenomenon is coupled to diminished mitochondrial activity, anerobiosis, and the channeling of α-ketoacids towards anti-oxidant defense. The resulting metabolic reconfiguration leads to fat accumulation and a reduction in ATP synthesis, characteristics that are common to numerous medical disorders. Hence, the ability of Al toxicity to create an oxidative environment promotes dysfunctional metabolic processes in astrocytes and hepatocytes. These molecular events triggered by Al-induced ROS production are the potential mediators of brain and liver disorders.
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Affiliation(s)
- Sungwon Han
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, P3E 2C6, Canada
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Auger C, Lemire J, Cecchini D, Bignucolo A, Appanna VD. The metabolic reprogramming evoked by nitrosative stress triggers the anaerobic utilization of citrate in Pseudomonas fluorescens. PLoS One 2011; 6:e28469. [PMID: 22145048 PMCID: PMC3228765 DOI: 10.1371/journal.pone.0028469] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 11/08/2011] [Indexed: 02/01/2023] Open
Abstract
Nitrosative stress is an ongoing challenge that most organisms have to contend with. When nitric oxide (NO) that may be generated either exogenously or endogenously encounters reactive oxygen species (ROS), it produces a set of toxic moieties referred to as reactive nitrogen species (RNS). As these RNS can severely damage essential biomolecules, numerous organisms have evolved elaborate detoxification strategies to nullify RNS. However, the contribution of cellular metabolism in fending off nitrosative stress is poorly understood. Using a variety of functional proteomic and metabolomic analyses, we have identified how the soil microbe Pseudomonas fluorescens reprogrammed its metabolic networks to survive in an environment enriched by sodium nitroprusside (SNP), a generator of nitrosative stress. To combat the RNS-induced ineffective aconitase (ACN) and tricarboxylic acid (TCA) cycle, the microbe invoked the participation of citrate lyase (CL), phosphoenolpyruvate carboxylase (PEPC) and pyruvate phosphate dikinase (PPDK) to convert citrate, the sole source of carbon into pyruvate and ATP. These enzymes were not evident in the control conditions. This metabolic shift was coupled to the concomitant increase in the activities of such classical RNS detoxifiers as nitrate reductase (NR), nitrite reductase (NIR) and S-nitrosoglutathione reductase (GSNOR). Hence, metabolism may hold the clues to the survival of organisms subjected to nitrosative stress and may provide therapeutic cues against RNS-resistant microbes.
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Affiliation(s)
- Christopher Auger
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Joseph Lemire
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Dominic Cecchini
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Adam Bignucolo
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Vasu D. Appanna
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
- * E-mail:
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Lemire J, Appanna VD. Aluminum toxicity and astrocyte dysfunction: a metabolic link to neurological disorders. J Inorg Biochem 2011; 105:1513-7. [PMID: 22099161 DOI: 10.1016/j.jinorgbio.2011.07.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 06/21/2011] [Accepted: 07/08/2011] [Indexed: 12/21/2022]
Abstract
Aluminum (Al) has been implicated in a variety of neurological diseases. However, the molecular mechanisms that enable Al to be involved in these disorders have yet to be fully delineated. Using astrocytes as a model of the cerebral cellular system, we have uncovered the biochemical networks that are affected by Al toxicity. In this review, we reveal how the inhibitory influence of Al on ATP production and on mitochondrial functions help generate globular astrocytes that are fat producing machines. These biological events may be the contributing factors to Al-triggered brain disorders.
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Affiliation(s)
- Joseph Lemire
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada P3E 2C6
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Mailloux RJ, Lemire J, Appanna VD. Hepatic response to aluminum toxicity: dyslipidemia and liver diseases. Exp Cell Res 2011; 317:2231-8. [PMID: 21787768 DOI: 10.1016/j.yexcr.2011.07.009] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 07/08/2011] [Accepted: 07/09/2011] [Indexed: 10/17/2022]
Abstract
Aluminum (Al) is a metal toxin that has been implicated in the etiology of a number of diseases including Alzheimer's, Parkinson's, dialysis encephalopathy, and osteomalacia. Al has been shown to exert its effects by disrupting lipid membrane fluidity, perturbing iron (Fe), magnesium, and calcium homeostasis, and causing oxidative stress. However, the exact molecular targets of aluminum's toxicity have remained elusive. In the present review, we describe how the use of a systems biology approach in cultured hepatoblastoma cells (HepG2) allowed the identification of the molecular targets of Al toxicity. Mitochondrial metabolism is the main site of the toxicological action of Al. Fe-dependent and redox sensitive enzymes in the tricarboxylic acid (TCA) cycle and oxidative phosphorylation (OXPHOS) are dramatically decreased by Al exposure. In an effort to compensate for diminished mitochondrial function, Al-treated cells stabilize hypoxia inducible factor-1α (HIF-1α) to increase ATP production by glycolysis. Additionally, Al toxicity leads to an increase in intracellular lipid accumulation due to enhanced lipogenesis and a decrease in the β-oxidation of fatty acids. Central to these effects is the alteration of α-ketoglutarate (KG) homeostasis. In Al-exposed cells, KG is preferentially used to quench ROS leading to succinate accumulation and HIF-1α stabilization. Moreover, the channeling of KG to combat oxidative stress leads to a reduction of l-carnitine biosynthesis and a concomitant decrease in fatty acid oxidation. The fluidity and interaction of these metabolic modules and the implications of these findings in liver-related disorders are discussed herein.
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Affiliation(s)
- Ryan J Mailloux
- Laurentian University, Department of Chemistry and Biochemistry, Canada
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Lemire J, Mailloux R, Darwich R, Auger C, Appanna VD. The disruption of L-carnitine metabolism by aluminum toxicity and oxidative stress promotes dyslipidemia in human astrocytic and hepatic cells. Toxicol Lett 2011; 203:219-26. [PMID: 21439360 DOI: 10.1016/j.toxlet.2011.03.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 03/11/2011] [Accepted: 03/14/2011] [Indexed: 12/19/2022]
Abstract
L-Carnitine is a critical metabolite indispensable for the metabolism of lipids as it facilitates fatty acid transport into the mitochondrion where β-oxidation occurs. Human astrocytes (CCF-STTG1 cells) and hepatocytes (HepG2 cells) exposed to aluminum (Al) and hydrogen peroxide (H₂O₂), were characterized with lower levels of L-carnitine, diminished β-oxidation, and increased lipid accumulation compared to the controls. γ-Butyrobetainealdehyde dehydrogenase (BADH) and butyrobetaine dioxygenase (BBDOX), two key enzymes mediating the biogenesis of L-carnitine, were sharply reduced during Al and H₂O₂ challenge. Exposure of the Al and H₂O₂-treated cells to α-ketoglutarate (KG), led to the recovery of L-carnitine production with the concomitant reduction in ROS levels. It appears that the channeling of KG to combat oxidative stress results in decreased L-carnitine synthesis, an event that contributes to the dyslipidemia observed during Al and H₂O₂ insults in these mammalian cells. Hence, KG may help alleviate pathological conditions induced by oxidative stress.
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Affiliation(s)
- Joseph Lemire
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E2C6, Canada
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Lemire J, Milandu Y, Auger C, Bignucolo A, Appanna VP, Appanna VD. Histidine is a source of the antioxidant, alpha-ketoglutarate, in Pseudomonas fluorescens challenged by oxidative stress. FEMS Microbiol Lett 2010; 309:170-7. [PMID: 20597986 DOI: 10.1111/j.1574-6968.2010.02034.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The role of alpha-ketoglutarate (KG) in the detoxification of reactive oxygen species (ROS) has only recently begun to be appreciated. This ketoacid neutralizes ROS in an NADPH-independent manner with the concomitant formation of succinate and CO(2). To further probe this intriguing attribute of KG in living systems, we have evaluated the significance of histidine metabolism in the model organism, Pseudomonas fluorescens, challenged by hydrogen peroxide (H(2)O(2)). Here, we show that this amino acid does contribute to KG homeostasis and appears to be earmarked for the production of KG during oxidative stress. Both the NAD- and the NADP-dependent glutamate dehydrogenases were upregulated in the stressed cells despite the sharp decline in the activities of numerous enzymes mediating the tricarboxylic acid cycle and oxidative phosphorylation. Enzymes such as isocitrate dehydrogenase-NAD dependent, succinate dehydrogenase, alpha-ketoglutarate dehydrogenase, Complex I, and Complex IV were severely affected in the P. fluorescens grown in the presence of H(2)O(2). Studies with fluorocitrate, a potent inhibitor of citrate metabolism, clearly revealed that histidine was preferentially utilized in the production of KG in the H(2)O(2)-challenged cells. Regulation experiments also helped confirm that the metabolic reprogramming, resulting in the enhanced production of KG was induced by H(2)O(2) stress. These data further establish the pivotal role that KG plays in antioxidative defense.
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Affiliation(s)
- Joseph Lemire
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, Canada
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Dehne N, Hintereder G, Brüne B. High glucose concentrations attenuate hypoxia-inducible factor-1alpha expression and signaling in non-tumor cells. Exp Cell Res 2010; 316:1179-89. [PMID: 20184881 DOI: 10.1016/j.yexcr.2010.02.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 01/15/2010] [Accepted: 02/16/2010] [Indexed: 10/19/2022]
Abstract
Hypoxia-inducible factor (HIF) is the major transcription factor mediating adaption to hypoxia e.g. by enhancing glycolysis. In tumor cells, high glucose concentrations are known to increase HIF-1alpha expression even under normoxia, presumably by enhancing the concentration of tricarboxylic acid cycle intermediates, while reactions of non-tumor cells are not well defined. Therefore, we analyzed cellular responses to different glucose concentrations in respect to HIF activation comparing tumor to non-tumor cells. Using cells derived from non-tumor origin, we show that HIF-1alpha accumulation was higher under low compared to high glucose concentrations. Low glucose allowed mRNA expression of HIF-1 target genes like adrenomedullin. Transfection of C(2)C(12) cells with a HIF-1alpha oxygen-dependent degradation domaine-GFP fusion protein revealed that prolyl hydroxylase (PHD) activity is impaired at low glucose concentrations, thus stabilizing the fusion protein. Mechanistic considerations suggested that neither O(2) redistribution nor an altered redox state explains impaired PHD activity in the absence of glucose. In order to affect PHD activity, glucose needs to be metabolized. Amino acids present in the medium also diminished HIF-1alpha expression, while the addition of fatty acids did not. This suggests that glucose or amino acid metabolism increases oxoglutarate concentrations, which enhances PHD activity in non-tumor cells. Tumor cells deprived of glutamine showed HIF-1alpha accumulation in the absence of glucose, proposing that enhanced glutaminolysis observed in many tumors enables these cells to compensate reduced oxoglutarate production in the absence of glucose.
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Affiliation(s)
- Nathalie Dehne
- Institute of Biochemistry I/ZAFES, Frankfurt am Main, Germany.
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Paddenberg R, Howold N, Hoger C, Janssen H, Grau V, Kummer W. Organ preservation solutions attenuate accumulation and nuclear translocation of hypoxia-inducible factor-1alpha in the hepatoma cell line HepG2. Cell Biochem Funct 2010; 27:516-25. [PMID: 19821261 DOI: 10.1002/cbf.1608] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Hypoxia-inducible factor-1alpha (HIF-1alpha) is a key transcription factor orchestrating hypoxic and inflammatory reactions. Here, we determined the impact of organ preservation solutions (Celsior; histidine-tryptophan-ketoglutarate solution, HTK; University of Wisconsin solution; UW), oxygen supply, and temperature on HIF-1alpha accumulation, recorded by Western blotting and immunocytochemistry, in the human hepatoma cell line HepG2. Generation of reactive oxygen species (ROS), NO, and cell viability were concomitantly assessed. At 4 degrees C, HIF-1alpha accumulation was not detectable. In normothermic (37 degrees C) cell culture medium (Dulbecco's Modified Eagle's Medium, DMEM), HepG2 cells accumulated HIF-1alpha even in normoxia (21% O(2)) which was not observed in either of the preservation solutions. This correlated to high generation of NO, a normoxic stabilizer of HIF-1alpha, and L-arginine content (substrate for NO synthesis) in DMEM, and low NO production and absence of L-arginine in preservation solutions. In normothermic hypoxia up to 24 h, intracellular HIF-1alpha accumulated in all conditions, but less in preservation solutions compared to DMEM. The inhibitory effect on accumulation and nuclear translocation was most prominent for HTK, the only solution containing the activator of HIF-1alpha degradation, alpha-ketoglutarate. Addition of other intermediates of the tricarbon acid cycle-succinate, fumarate, malate-did not alter HIF-1alpha accumulation, although succinate exhibited a beneficial effect on cell viability in cold storage. In conclusion, preservation solutions attenuate accumulation and nuclear translocation of the transcription factor HIF-1alpha, and this property is seemingly related to their chemical composition (L-arginine, alpha-ketoglutarate). Thus, it appears feasible to design preservation solution specifically to modify HIF-1alpha accumulation and nuclear translocation.
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Affiliation(s)
- Renate Paddenberg
- Institute for Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany.
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Ezomo OF, Matsushima F, Meshitsuka S. Up-regulation in the expression of renin gene by the influence of aluminium. J Inorg Biochem 2009; 103:1563-70. [DOI: 10.1016/j.jinorgbio.2009.07.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2009] [Revised: 06/06/2009] [Accepted: 07/13/2009] [Indexed: 10/20/2022]
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Singh R, Lemire J, Mailloux RJ, Chénier D, Hamel R, Appanna VD. An ATP and oxalate generating variant tricarboxylic acid cycle counters aluminum toxicity in Pseudomonas fluorescens. PLoS One 2009; 4:e7344. [PMID: 19809498 PMCID: PMC2752808 DOI: 10.1371/journal.pone.0007344] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Accepted: 09/11/2009] [Indexed: 01/05/2023] Open
Abstract
Although the tricarboxylic acid (TCA) cycle is essential in almost all aerobic organisms, its precise modulation and integration in global cellular metabolism is not fully understood. Here, we report on an alternative TCA cycle uniquely aimed at generating ATP and oxalate, two metabolites critical for the survival of Pseudomonas fluorescens. The upregulation of isocitrate lyase (ICL) and acylating glyoxylate dehydrogenase (AGODH) led to the enhanced synthesis of oxalate, a dicarboxylic acid involved in the immobilization of aluminum (Al). The increased activity of succinyl-CoA synthetase (SCS) and oxalate CoA-transferase (OCT) in the Al-stressed cells afforded an effective route to ATP synthesis from oxalyl-CoA via substrate level phosphorylation. This modified TCA cycle with diminished efficacy in NADH production and decreased CO(2)-evolving capacity, orchestrates the synthesis of oxalate, NADPH, and ATP, ingredients pivotal to the survival of P. fluorescens in an Al environment. The channeling of succinyl-CoA towards ATP formation may be an important function of the TCA cycle during anaerobiosis, Fe starvation and O(2)-limited conditions.
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Affiliation(s)
- Ranji Singh
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Joseph Lemire
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Ryan J. Mailloux
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Daniel Chénier
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Robert Hamel
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Vasu D. Appanna
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
- * E-mail:
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Matsumoto K, Obara N, Ema M, Horie M, Naka A, Takahashi S, Imagawa S. Antitumor effects of 2-oxoglutarate through inhibition of angiogenesis in a murine tumor model. Cancer Sci 2009; 100:1639-47. [PMID: 19575748 PMCID: PMC11159297 DOI: 10.1111/j.1349-7006.2009.01249.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Revised: 05/27/2009] [Accepted: 05/28/2009] [Indexed: 11/29/2022] Open
Abstract
Hypoxia-inducible factor 1 (HIF-1) plays essential roles in tumor angiogenesis and growth by regulating the transcription of several key genes in response to hypoxic stress and growth factors. HIF-1 is a heterodimeric transcriptional activator consisting of inducible alpha and constitutive beta subunits. In oxygenated cells, proteins containing the prolyl hydroxylase domain (PHD) directly sense intracellular oxygen concentrations. PHDs tag HIF-1alpha subunits for polyubiquitination and proteasomal degradation by prolyl hydroxylation using 2-oxoglutarate (2-OX) and dioxygen. Our recent studies showed that 2-OX reduces HIF-1alpha, erythropoietin, and vascular endothelial growth factor (VEGF) expression in the hepatoma cell line Hep3B when under hypoxic conditions in vitro. Here, we report that similar results were obtained in Lewis lung cancer (LLC) cells in in vitro studies. Furthermore, 2-OX showed potent antitumor effects in a mouse dorsal air sac assay and a murine tumor xenograft model. In the dorsal air sac assay, 2-OX reduced the numbers of newly formed vessels induced by LLC cells. In a murine tumor xenograft model, intraperitoneal injection of 2-OX significantly inhibited tumor growth and angiogenesis in tumor tissues. Moreover, 5-fluorouracil combined with 2-OX significantly inhibited tumor growth in this model, which was accompanied by reduction of Vegf gene expression and inhibited angiogenesis in tumor tissues. These results suggest that 2-OX is a promising anti-angiogenic therapeutic agent.
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MESH Headings
- Angiogenesis Inhibitors/therapeutic use
- Animals
- Blotting, Western
- Carcinoma, Lewis Lung/blood supply
- Carcinoma, Lewis Lung/drug therapy
- Carcinoma, Lewis Lung/pathology
- Cell Proliferation
- Enzyme-Linked Immunosorbent Assay
- Flow Cytometry
- Fluorouracil/therapeutic use
- Humans
- Hypoxia-Inducible Factor 1, alpha Subunit/genetics
- Hypoxia-Inducible Factor 1, alpha Subunit/metabolism
- Immunoenzyme Techniques
- Ketoglutaric Acids/therapeutic use
- Male
- Melanoma, Experimental/blood supply
- Melanoma, Experimental/drug therapy
- Melanoma, Experimental/pathology
- Mice
- Mice, Inbred C57BL
- Neovascularization, Pathologic/prevention & control
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Tumor Cells, Cultured
- Vascular Endothelial Growth Factor A/metabolism
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Ken Matsumoto
- Division of Hematology, Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
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Alpha-ketoglutarate dehydrogenase and glutamate dehydrogenase work in tandem to modulate the antioxidant alpha-ketoglutarate during oxidative stress in Pseudomonas fluorescens. J Bacteriol 2009; 191:3804-10. [PMID: 19376872 DOI: 10.1128/jb.00046-09] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Alpha-ketoglutarate (KG) is a crucial metabolite in all living organisms, as it participates in a variety of biochemical processes. We have previously shown that this keto acid is an antioxidant and plays a key role in the detoxification of reactive oxygen species (ROS). In an effort to further confirm this intriguing phenomenon, Pseudomonas fluorescens was exposed to menadione-containing media, with various amino acids as the sources of nitrogen. Here, we demonstrate that KG dehydrogenase (KGDH) and NAD-dependent glutamate dehydrogenase (GDH) work in tandem to modulate KG homeostasis. While KGDH was sharply decreased in cells challenged with menadione, GDH was markedly increased in cultures containing arginine (Arg), glutamate (Glu), and proline (Pro). When ammonium (NH(4)) was utilized as the nitrogen source, both KGDH and GDH levels were diminished. These enzymatic profiles were reversed when control cells were incubated in menadione media. (13)C nuclear magnetic resonance and high-performance liquid chromatography studies revealed how KG was utilized to eliminate ROS with the concomitant formation of succinate. The accumulation of KG in the menadione-treated cells was dependent on the redox status of the lipoic acid residue in KGDH. Indeed, the treatment of cellular extracts from the menadione-exposed cells with dithiothreitol, a reducing agent, partially restored the activity of KGDH. Taken together, these data reveal that KG is pivotal to the antioxidative defense strategy of P. fluorescens and also point to the ROS-sensing role for KGDH.
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