1
|
Yu Y, Pi S, Ke T, Zhou B, Chao W, Yang Y, Li Z, Li G, Ren N, Gao X, Lu L. Artificial Soil-Like Material Enhances CO 2 Bio-Valorization into Chemicals in Gas Fermentation. ACS APPLIED MATERIALS & INTERFACES 2023; 15:53488-53497. [PMID: 37929338 DOI: 10.1021/acsami.3c12627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2023]
Abstract
Gas fermentation offers a carbon-neutral route for producing industrial feedstocks using autotrophic microbes to convert carbon dioxide (CO2) in waste gases, such as industrial emissions and biogas, into valuable chemicals or biofuels. However, slow microbial metabolism owing to low gaseous solubility causes significant challenges in gas fermentation. Although chemical or genetic manipulations have been explored to improve gas fermentation, they are either nonsustainable or complex. Herein, an artificial soil-like material (SLM) inspired by natural soil was fabricated to improve the growth and metabolism ofCupriavidus necatorfor enhanced poly-β-hydroxybutyrate (PHB) biosynthesis from CO2 and hydrogen (H2). Porous SLM comprises low-cost nanoclay, boehmite, and starch and serves as a biocarrier to facilitate the colonization of bacteria and delivery of CO2 to bacteria. With 3.0 g/L SLM addition, the solubility of CO2 in water increased by ∼4 times and biomass and PHB production boosted by 29 and 102%, respectively, in the 24 h culture. In addition, a positive modulation was observed in the metabolism of PHB biosynthesis. PHB biosynthesis-associated gene expression was found to be enhanced in response to the SLM addition. The concentrations of intermediates in the metabolic pathway of PHB biosynthesis, such as pyruvate and acetyl-CoA, as well as reducing energy (ATP and NADPH) significantly increased with SLM addition. SLM also demonstrated the merits of easy fabrication, high stability, recyclability, and plasticity, thereby indicating its considerable potential for large-scale application in gas fermentation.
Collapse
Affiliation(s)
- Yongjie Yu
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, China
| | - Shanshan Pi
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, China
| | - Tan Ke
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, China
| | - Baiqin Zhou
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, China
| | - Weixiang Chao
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, China
| | - Yang Yang
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, China
| | - Zhida Li
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, China
| | - Guifeng Li
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, China
| | - Nanqi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, China
| | - Xiang Gao
- Center for Materials Synthetic Biology, CAS Key Laboratory of Quantitative Engineering Biology of CAS, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academic of Science, Shenzhen 518000, China
| | - Lu Lu
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, China
| |
Collapse
|
2
|
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: 8] [Impact Index Per Article: 8.0] [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.
Collapse
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
| |
Collapse
|
3
|
Vaziri AS, Ghorbanzadeh R, Hosseinpour-Nader A. Rutin-gallium complex mediated antimicrobial photodynamic therapy: An in vitro studies against Streptococcus mutans biofilms. Photodiagnosis Photodyn Ther 2023; 42:103367. [PMID: 36842472 DOI: 10.1016/j.pdpdt.2023.103367] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 02/16/2023] [Accepted: 02/22/2023] [Indexed: 02/28/2023]
Abstract
BACKGROUND Discoloration of teeth following antimicrobial photodynamic therapy (aPDT) is a serious concern. Common photosensitizers are colored, and access to a photosensitizer that does not leave color on the teeth or is the same color as the enamel and dentin is highly demanded. The physicochemical characterization, anti-virulence, and antimicrobial effects of a novel rutin-gallium (III) (Rt-Ga) complex as novel photosensitizer are presented herein. MATERIALS AND METHODS Photophysical properties and cytotoxicity of the Rt-Ga complex were evaluated in comparison with the parental rutin. Intracellular reactive oxygen species (ROS) generation following Rt-Ga complex-mediated aPDT was measured using the fluorescent 2',7'-dichlorofluorescein diacetate (H2DCF-DA) method. The anti-biofilm effects of Rt-Ga complex-mediated aPDT on Streptococcus mutans were assessed using a colorimetric assay. The virulence‑associated gtfB gene expression was assessed following Rt-Ga complex-mediated aPDT by quantitative real‑time PCR. RESULTS The photophysical properties of the Rt-Ga complex revealed a significant blue-shift in absorption (60 nm shift) and increased extinction coefficient (4100 M -1 cm -1; at λmax = 450 nm). Average (± SEM) DCF fluorescence intensities in an arbitrary unit (A.U.) were 7.1 ± 0.9, 4.1 ± 0.5, and 1.7 ± 0.3 for 10.0 μM of Rt-Ga complex-mediated aPDT, 7.5 μM of Rt-Ga complex-mediated aPDT, and 10.0 μM of Rt-Ga complex alone, respectively. The corresponding DCF fluorescence intensities were 710% (P = 0.001), 410% (P = 0.001), and 170% (P = 0.02) of the untreated S. mutans as the control group (1.0 ± 0.1 A.U.), respectively. The novel Rt-Ga complex-mediated aPDT exhibited no toxicity against primary human gingival fibroblast cells, a dose dependent decrease in S. mutans biofilm cell survival and virulence were observed (91.4% and 11.7-fold, respectively). CONCLUSION The Rt-Ga complex-mediated anti-virulence and antimicrobial photodynamic effects were superior to the one caused by rutin alone making the Rt-Ga complex a more promising photosensitizer than the parent material.
Collapse
Affiliation(s)
- Abbas Salehi Vaziri
- Department of Orthodontics, School of Dentistry, Shahed University, Tehran, Iran
| | | | | |
Collapse
|
4
|
Legendre F, MacLean A, Tharmalingam S, Appanna VD. Metabolic adaptation and ATP homeostasis in Pseudomonas fluorescens exposed to phosphate stress. World J Microbiol Biotechnol 2022; 38:255. [DOI: 10.1007/s11274-022-03432-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 10/05/2022] [Indexed: 11/06/2022]
|
5
|
Zhang C, Yang B, Biazik JM, Webster RF, Xie W, Tang J, Allioux FM, Abbasi R, Mousavi M, Goldys EM, Kilian KA, Chandrawati R, Esrafilzadeh D, Kalantar-Zadeh K. Gallium Nanodroplets are Anti-Inflammatory without Interfering with Iron Homeostasis. ACS NANO 2022; 16:8891-8903. [PMID: 35613428 DOI: 10.1021/acsnano.1c10981] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Gallium (Ga) compounds, as the source of Ga ions (Ga3+), have been historically used as anti-inflammatories. Currently, the widely accepted mechanisms of the anti-inflammatory effects for Ga3+ are rationalized on the basis of their similarities to ferric ions (Fe3+), which permits Ga3+ to bind with Fe-binding proteins and subsequently disturbs the Fe homeostasis in the immune cells. Here in contrast to the classic views, our study presents the mechanisms of Ga as anti-inflammatory by delivering Ga nanodroplets (GNDs) into lipopolysaccharide-induced macrophages and exploring the processes. The GNDs show a selective inhibition of nitric oxide (NO) production without affecting the accumulation of pro-inflammatory mediators. This is explained by GNDs disrupting the synthesis of inducible NO synthase in the activated macrophages by upregulating the levels of eIF2α phosphorylation, without interfering with the Fe homeostasis. The Fe3+ transferrin receptor-independent endocytosis of GNDs by the cells prompts a fundamentally different mechanism as anti-inflammatories in comparison to that imparted by Ga3+. This study reveals the fundamental molecular basis of GND-macrophage interactions, which may provide additional avenues for the use of Ga for anti-inflammatory and future biomedical and pharmaceutical applications.
Collapse
Affiliation(s)
- Chengchen Zhang
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Biyao Yang
- ARC Centre of Excellence for Nanoscale BioPhotonics, Graduate School of Biomedical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Joanna M Biazik
- Electron Microscope Unit, Mark Wainwright Analytical Centre, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Richard F Webster
- Electron Microscope Unit, Mark Wainwright Analytical Centre, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Wanjie Xie
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Jianbo Tang
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Francois-Marie Allioux
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Roozbeh Abbasi
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Maedehsadat Mousavi
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Ewa M Goldys
- ARC Centre of Excellence for Nanoscale BioPhotonics, Graduate School of Biomedical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Kristopher A Kilian
- School of Chemistry, School of Materials Science and Engineering, Australian Centre for NanoMedicine, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Rona Chandrawati
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Dorna Esrafilzadeh
- Graduate School of Biomedical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Kourosh Kalantar-Zadeh
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| |
Collapse
|
6
|
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.
Collapse
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:
| |
Collapse
|
7
|
El-sonbaty SM, Moawed FSM, Kandil EI, M Tamamm A. Antitumor and Antibacterial Efficacy of Gallium Nanoparticles Coated by Ellagic Acid. Dose Response 2022; 20:15593258211068998. [PMID: 35173563 PMCID: PMC8841935 DOI: 10.1177/15593258211068998] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 12/06/2021] [Indexed: 12/24/2022] Open
Abstract
Cancer is a mortality contributor worldwide, and breast cancer is the most common among women. Despite the numerous breast cancer therapeutic strategies, they either have limitations or sometimes are resisted by cancer, so new approaches are needed to tackle those restrictions. Nanotechnology offers exciting leaps in the diagnosis and treatment of cancer, especially breast cancer. The main objective of this study was to investigate the effect of the newly synthesized gallium nanoparticles coated by Ellagic acid (EA-GaNPs) on the induced mammary gland carcinogenesis in female rats and their antibacterial activities comparison with standard antibiotics (Ketoconazole (100 μg/ml) and Gentamycin (4 μg/ml)) by disc diffusion method using eight different microbial species. The antitumor efficacy of EA-GaNPs was conducted both in vitro and in in vivo. The result of antimicrobial activity of EA-Ga NPs (1 mg/1 mL) revealed moderate toxicity behavior against Gram-positive {Staphylococcus aureus, Bacillus subtilis, Bacillus cereus) and Gram-negative pathogenic bacteria {Escherichia coli, Proteus vulgarfs) also, antifungal activity was detected against {Aspergillus terreus). In vitro study showed that EA-GaNPs inhibited human breast cancer cell line (MCF-7) proliferation with IC50 of 2.86 μg/ml. Although in vivo; the administration of EA-GaNPs to DMBA-treated rats ameliorated the hyperplastic state of mammary gland carcinogenesis induced by DMBA. Additionally, EA-GaNPs administration significantly modulated the activities of ALT and AST, as well as the levels of urea and creatinine in serum. Also, EA-GaNPs administration improved the antioxidant state by increasing Superoxide dismutase activity and GSH content, and decreasing malondialdehyde content in the mammary tissue, besides enhancing the apoptotic activity through elevating the levels of caspase-3 and decreasing the protein intensities of protein kinase B & phosphatidyl inositide 3-kinases. Furthermore, a significant decrease in serum Total iron-binding capacity accompanied by a significant increase in the level of calcium was noted. So, it can be concluded that the newly synthesized nanoparticles EA-GaNPs have an efficient antitumor activity that was manifested by reduction of the viability on the human breast cancer cell line (MCF-7) in vitro. Also, in vivo against the chemically induced mammary gland carcinogenesis in a female rat model. Histopathological findings were in harmony with biochemical and molecular results showing the effectiveness of EA-GaNPs against mammary carcinogenesis. Therefore, EA-GaNPs could be a promising, potent anti-cancer compound.
Collapse
Affiliation(s)
- Sawsan M El-sonbaty
- Radiation Microbiology Department, National Center for Radiation Research and Technology, Egyptian Atomic Energy Authority, Cairo, Egypt
| | - Fatma SM Moawed
- Health Radiation Research Department, National Center for Radiation Research and Technology, Egyptian Atomic Energy Authority, Cairo, Egypt
| | - Eman I Kandil
- Biochemistry Department, Faculty of Science, Ain Shams University, Cairo, Egypt
| | - Amira M Tamamm
- Biochemistry Department, Faculty of Science, Ain Shams University, Cairo, Egypt
| |
Collapse
|
8
|
Li F, Liu F, Huang K, Yang S. Advancement of Gallium and Gallium-Based Compounds as Antimicrobial Agents. Front Bioeng Biotechnol 2022; 10:827960. [PMID: 35186906 PMCID: PMC8855063 DOI: 10.3389/fbioe.2022.827960] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 01/13/2022] [Indexed: 12/30/2022] Open
Abstract
With the abuse and misuse of antibiotics, antimicrobial resistance has become a challenging issue in the medical system. Iatrogenic and non-iatrogenic infections caused by multidrug-resistant (MDR) pathogens pose serious threats to global human life and health because the efficacy of traditional antibiotics has been greatly reduced and the resulting socio-economic burden has increased. It is important to find and develop non-antibiotic-dependent antibacterial strategies because the development of new antibiotics can hardly keep pace with the emergence of resistant bacteria. Gallium (III) is a multi-target antibacterial agent that has an excellent antibacterial activity, especially against MDR pathogens; thus, a gallium (III)-based treatment is expected to become a new antibacterial strategy. However, some limitations of gallium ions as antimicrobials still exist, including low bioavailability and explosive release. In recent years, with the development of nanomaterials and clathrates, the progress of manufacturing technology, and the emergence of synergistic antibacterial strategies, the antibacterial activities of gallium have greatly improved, and the scope of application in medical systems has expanded. This review summarizes the advancement of current optimization for these key factors. This review will enrich the knowledge about the efficiency and mechanism of various gallium-based antibacterial agents and provide strategies for the improvement of the antibacterial activity of gallium-based compounds.
Collapse
Affiliation(s)
| | - Fengxiang Liu
- *Correspondence: Fengxiang Liu, ; Kai Huang, ; Shengbing Yang,
| | - Kai Huang
- *Correspondence: Fengxiang Liu, ; Kai Huang, ; Shengbing Yang,
| | - Shengbing Yang
- *Correspondence: Fengxiang Liu, ; Kai Huang, ; Shengbing Yang,
| |
Collapse
|
9
|
Baggio G, Groves RA, Chignola R, Piacenza E, Presentato A, Lewis IA, Lampis S, Vallini G, Turner RJ. Untargeted Metabolomics Investigation on Selenite Reduction to Elemental Selenium by Bacillus mycoides SeITE01. Front Microbiol 2021; 12:711000. [PMID: 34603239 PMCID: PMC8481872 DOI: 10.3389/fmicb.2021.711000] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 08/16/2021] [Indexed: 12/02/2022] Open
Abstract
Bacillus mycoides SeITE01 is an environmental isolate that transforms the oxyanion selenite (SeO 3 2 - ) into the less bioavailable elemental selenium (Se0) forming biogenic selenium nanoparticles (Bio-SeNPs). In the present study, the reduction of sodium selenite (Na2SeO3) by SeITE01 strain and the effect ofSeO 3 2 - exposure on the bacterial cells was examined through untargeted metabolomics. A time-course approach was used to monitor both cell pellet and cell free spent medium (referred as intracellular and extracellular, respectively) metabolites in SeITE01 cells treated or not withSeO 3 2 - . The results show substantial biochemical changes in SeITE01 cells when exposed toSeO 3 2 - . The initial uptake ofSeO 3 2 - by SeITE01 cells (3h after inoculation) shows both an increase in intracellular levels of 4-hydroxybenzoate and indole-3-acetic acid, and an extracellular accumulation of guanosine, which are metabolites involved in general stress response adapting strategies. Proactive and defensive mechanisms againstSeO 3 2 - are observed between the end of lag (12h) and beginning of exponential (18h) phases. Glutathione and N-acetyl-L-cysteine are thiol compounds that would be mainly involved in Painter-type reaction for the reduction and detoxification ofSeO 3 2 - to Se0. In these growth stages, thiol metabolites perform a dual role, both acting against the toxic and harmful presence of the oxyanion and as substrate or reducing sources to scavenge ROS production. Moreover, detection of the amino acids L-threonine and ornithine suggests changes in membrane lipids. Starting from stationary phase (24 and 48h), metabolites related to the formation and release of SeNPs in the extracellular environment begin to be observed. 5-hydroxyindole acetate, D-[+]-glucosamine, 4-methyl-2-oxo pentanoic acid, and ethanolamine phosphate may represent signaling strategies following SeNPs release from the cytoplasmic compartment, with consequent damage to SeITE01 cell membranes. This is also accompanied by intracellular accumulation of trans-4-hydroxyproline and L-proline, which likely represent osmoprotectant activity. The identification of these metabolites suggests the activation of signaling strategies that would protect the bacterial cells fromSeO 3 2 - toxicity while it is converting into SeNPs.
Collapse
Affiliation(s)
- Greta Baggio
- Department of Biotechnology, University of Verona, Verona, Italy
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Ryan A. Groves
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Roberto Chignola
- Department of Biotechnology, University of Verona, Verona, Italy
| | - Elena Piacenza
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Palermo, Italy
| | - Alessandro Presentato
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Palermo, Italy
| | - Ian A. Lewis
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Silvia Lampis
- Department of Biotechnology, University of Verona, Verona, Italy
| | - Giovanni Vallini
- Department of Biotechnology, University of Verona, Verona, Italy
| | - Raymond J. Turner
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| |
Collapse
|
10
|
Li K, Tian H, Guo A, Jin L, Chen W, Tao B. Gallium (Ga)-strontium (Sr) layered double hydroxide composite coating on titanium substrates for enhanced osteogenic and antibacterial abilities. J Biomed Mater Res A 2021; 110:273-286. [PMID: 34323363 DOI: 10.1002/jbm.a.37284] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 07/17/2021] [Accepted: 07/21/2021] [Indexed: 01/25/2023]
Abstract
Bacterial infection and poor osteogenic capacity can result in the loosing or failure of titanium (Ti)-based implants in the clinic. Therefore, it is urgent to design an effective approach to enhance the osteogenic property and restrict bacterial activity. In this study, a layered double hydroxide (LDH) composed of Ga and Sr ions on Ti substrates by a hydrothermal method, then calcined in 250°C and denoted as LDH250. The scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were confirmed that the LDH films were successfully formed on the Ti substrates. Importantly, the obtained LDH films can induce an alkaline microenvironment around the Ti surface and regulate the behaviors of osteogenic cells and bacteria. In vitro cellular experiments, the LDH250 can enhance the differentiation of both MC3T3-E1 cells and osteoblasts, stimulate alkaline phosphatase activity (ALP), collagen secretion, and mineralization levels. Meanwhile, antimicrobial assay against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) demonstrated that the LDH250 samples had strong antibacterial abilities, which attributed to the release profile of Ga3+ could act as a "Trojan horse" to destroy the bacterial iron metabolism, inducing of local alkaline environment, and producing reactive oxygen species. Hence, this study provides an effective method for reducing antibacterial infection and enhancing the bone integrative capacity of Ti-based implants for orthopedic applications.
Collapse
Affiliation(s)
- Kai Li
- Department of Orthopedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Hongchuan Tian
- Department of Orthopedics, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Ai Guo
- Department of Geriatrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Liguo Jin
- College of Chemistry, Nanchang University, Nanchang, Jiangxi, China
| | - Weizhen Chen
- Department of Laboratory Medicine, The First Affiliated Hospital, School of Medicine, Zhejiang University, Zhejiang, Hangzhou, China
| | - Bailong Tao
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| |
Collapse
|
11
|
Sergi R, Bellucci D, Cannillo V. A Review of Bioactive Glass/Natural Polymer Composites: State of the Art. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E5560. [PMID: 33291305 PMCID: PMC7730917 DOI: 10.3390/ma13235560] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 12/02/2020] [Accepted: 12/04/2020] [Indexed: 02/07/2023]
Abstract
Collagen, gelatin, silk fibroin, hyaluronic acid, chitosan, alginate, and cellulose are biocompatible and non-cytotoxic, being attractive natural polymers for medical devices for both soft and hard tissues. However, such natural polymers have low bioactivity and poor mechanical properties, which limit their applications. To tackle these drawbacks, collagen, gelatin, silk fibroin, hyaluronic acid, chitosan, alginate, and cellulose can be combined with bioactive glass (BG) nanoparticles and microparticles to produce composites. The incorporation of BGs improves the mechanical properties of the final system as well as its bioactivity and regenerative potential. Indeed, several studies have demonstrated that polymer/BG composites may improve angiogenesis, neo-vascularization, cells adhesion, and proliferation. This review presents the state of the art and future perspectives of collagen, gelatin, silk fibroin, hyaluronic acid, chitosan, alginate, and cellulose matrices combined with BG particles to develop composites such as scaffolds, injectable fillers, membranes, hydrogels, and coatings. Emphasis is devoted to the biological potentialities of these hybrid systems, which look rather promising toward a wide spectrum of applications.
Collapse
Affiliation(s)
| | | | - Valeria Cannillo
- Dipartimento di Ingegneria Enzo Ferrari, Università degli Studi di Modena e Reggio Emilia, Via P. Vivarelli 10, 41125 Modena, Italy; (R.S.); (D.B.)
| |
Collapse
|
12
|
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: 40] [Impact Index Per Article: 10.0] [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.
Collapse
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.
| |
Collapse
|
13
|
MacLean A, Bley AM, Appanna VP, Appanna VD. Metabolic manipulation by Pseudomonas fluorescens: a powerful stratagem against oxidative and metal stress. J Med Microbiol 2020; 69:339-346. [PMID: 31961786 DOI: 10.1099/jmm.0.001139] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Metabolism is the foundation of all living organisms and is at the core of numerous if not all biological processes. The ability of an organism to modulate its metabolism is a central characteristic needed to proliferate, to be dormant and to survive any assault. Pseudomonas fluorescens is bestowed with a uniquely versatile metabolic framework that enables the microbe to adapt to a wide range of conditions including disparate nutrients and toxins. In this mini-review we elaborate on the various metabolic reconfigurations evoked by this microbial system to combat reactive oxygen/nitrogen species and metal stress. The fine-tuning of the NADH/NADPH homeostasis coupled with the production of α-keto-acids and ATP allows for the maintenance of a reductive intracellular milieu. The metabolic networks propelling the synthesis of metabolites like oxalate and aspartate are critical to keep toxic metals at bay. The biochemical processes resulting from these defensive mechanisms provide molecular clues to thwart infectious microbes and reveal elegant pathways to generate value-added products.
Collapse
Affiliation(s)
- Alex MacLean
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6, Canada
| | - Anondo Michel Bley
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6, Canada
| | - Varun P Appanna
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6, Canada
| | - Vasu D Appanna
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6, Canada
| |
Collapse
|
14
|
Tovar-García A, Angarita-Zapata V, Cazares A, Jasso-Chávez R, Belmont-Díaz J, Sanchez-Torres V, López-Jacome LE, Coria-Jiménez R, Maeda T, García-Contreras R. Characterization of gallium resistance induced in a Pseudomonas aeruginosa cystic fibrosis isolate. Arch Microbiol 2019; 202:617-622. [DOI: 10.1007/s00203-019-01777-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 11/09/2019] [Accepted: 11/20/2019] [Indexed: 11/29/2022]
|
15
|
Duffin RN, Blair VL, Kedzierski L, Andrews PC. Alkyl gallium(III) quinolinolates: A new class of highly selective anti-leishmanial agents. Eur J Med Chem 2019; 186:111895. [PMID: 31771825 DOI: 10.1016/j.ejmech.2019.111895] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 11/15/2019] [Accepted: 11/15/2019] [Indexed: 12/12/2022]
Abstract
A series of eight alkyl gallium complexes of general formulae [GaMe2(L)] and [Ga(Me)2L] have been synthesised, characterised and their antimicrobial activity against bacteria, cancer cells and Leishmania assessed. All eight complexes are novel, with the solid-state structures of all complexes successfully authenticated by single crystal X-ray diffraction. The dimethyl complexes all adopt a four-coordinate tetrahedral confirmation, while the monomethyl complexes are five-coordinate trigonal bipyramidal. All complexes were screened for their anti-bacterial activity either by solution state diffusion, or a solid-state stab test. The five soluble complexes underwent testing against two differing mammalian cell controls, with excellent selectivity observed against COS-7 cells, with an IC50 range of 88.5 μM to ≥100 μM. Each soluble complex was also tested for their anti-cancer capabilities, with no significant activity observed. Excellent activity was exhibited against the protozoan parasite Leishmania major (strain: V121) in both the promastigote and amastigote forms, with IC50 values ranging from 1.11 μM-13.4 μM for their anti-promastigote activity and % infection values of 3.5% ± 0.65-11.5% ± 0.65 for the more clinically relevant amastigote. Selectivity indices for each were found to be in the ranges of 6.61-64.7, with significant selectivity noted for two of the complexes. At minimum, the gallium complexes show a 3-fold enhancement in activity towards the Leishmaniaamastigotes over the parent quinolinols alone.
Collapse
Affiliation(s)
- Rebekah N Duffin
- School of Chemistry, Monash University, Clayton, Melbourne, VIC, 3800, Australia
| | - Victoria L Blair
- School of Chemistry, Monash University, Clayton, Melbourne, VIC, 3800, Australia
| | - Lukasz Kedzierski
- Faculty of Veterinary and Agricultural Sciences at the Peter Doherty Institute for Infection and Immunity, 792 Elizabeth Street, Melbourne, 3000, Victoria, Australia
| | - Philip C Andrews
- School of Chemistry, Monash University, Clayton, Melbourne, VIC, 3800, Australia.
| |
Collapse
|
16
|
Todorov L, Kostova I, Traykova M. Lanthanum, Gallium and their Impact on Oxidative Stress. Curr Med Chem 2019; 26:4280-4295. [PMID: 31438825 DOI: 10.2174/0929867326666190104165311] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 08/10/2018] [Accepted: 12/16/2018] [Indexed: 12/14/2022]
Abstract
The role metals play in living organisms is well established and subject to extensive research. Some of them participate in electron-exchange reactions. Such reactions cause generation of free radicals that can adversely impact biological systems, as a result of oxidative stress. The impact of 'non-biological' metals on oxidative stress is also a worthy pursuit due to the crucial role they play in modern civilization. Lanthanides (Ln) are widely used in modern technology. As a result, human exposure to them is increasing. They have a number of established medical applications and are being extensively researched for their potential antiviral, anticancer and anti-inflammatory properties. The present review focuses on lanthanum (La) and its impact on oxidative stress. Another metal, widely used in modern high-tech is gallium (Ga). In some respects, it shows certain similarities to La, therefore it is a subject of the present review as well. Both metals exhibit ionic mimicry which allows them to specifically target malignant cells, initiating apoptosis that makes their simple salts and coordination complexes promising candidates for future anticancer agents.
Collapse
Affiliation(s)
- Lozan Todorov
- Department of Chemistry, Faculty of Pharmacy, Medical University, Sofia, Bulgaria
| | - Irena Kostova
- Department of Chemistry, Faculty of Pharmacy, Medical University, Sofia, Bulgaria
| | - Maria Traykova
- Department of Physics and Biophysics, Faculty of Medicine, Medical University, Sofia, Bulgaria
| |
Collapse
|
17
|
Zavatti V, Budman H, Legge RL, Tamer M. Impact of oxidative stress on protein production by Bordetella pertussis for vaccine production. Biochem Eng J 2019. [DOI: 10.1016/j.bej.2019.107359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
18
|
The race between drug introduction and appearance of microbial resistance. Current balance and alternative approaches. Curr Opin Pharmacol 2019; 48:48-56. [DOI: 10.1016/j.coph.2019.04.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 04/23/2019] [Accepted: 04/23/2019] [Indexed: 11/13/2022]
|
19
|
Clarkin OM, Wu B, Cahill PA, Brougham DF, Banerjee D, Brady SA, Fox EK, Lally C. Novel injectable gallium-based self-setting glass-alginate hydrogel composite for cardiovascular tissue engineering. Carbohydr Polym 2019; 217:152-159. [PMID: 31079672 DOI: 10.1016/j.carbpol.2019.04.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 04/01/2019] [Accepted: 04/02/2019] [Indexed: 11/19/2022]
Abstract
Composite biomaterials offer a new approach for engineering novel, minimally-invasive scaffolds with properties that can be modified for a range of soft tissue applications. In this study, a new way of controlling the gelation of alginate hydrogels using Ga-based glass particles is presented. Through a comprehensive analysis, it was shown that the setting time, mechanical strength, stiffness and degradation properties of this composite can all be tailored for various applications. Specifically, the hydrogel generated through using a glass particle, wherein toxic aluminium is replaced with biocompatible gallium, exhibited enhanced properties. The material's stiffness matches that of soft tissues, while it displays a slow and tuneable gelation rate, making it a suitable candidate for minimally-invasive intra-vascular injection. In addition, it was also found that this composite can be tailored to deliver ions into the local cellular environment without affecting platelet adhesion or compromising viability of vascular cells in vitro.
Collapse
Affiliation(s)
- Owen M Clarkin
- DCU Biomaterials Research Group, Centre for Medical Engineering Research, School of Mechanical and Manufacturing Engineering, Dublin City University, Dublin 9, Ireland
| | - Bing Wu
- DCU Biomaterials Research Group, Centre for Medical Engineering Research, School of Mechanical and Manufacturing Engineering, Dublin City University, Dublin 9, Ireland; DUBBLE Beamline, European Synchrotron Radiation Facility (ESRF), 71 avenue des Martyrs, CS 40220, Grenoble, 38043, France; School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Paul A Cahill
- Vascular Biology and Therapeutic Laboratory, School of Biotechnology, Faculty of Science and Health, Dublin City University, Dublin 9, Ireland
| | - Dermot F Brougham
- School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland
| | - Dipanjan Banerjee
- DUBBLE Beamline, European Synchrotron Radiation Facility (ESRF), 71 avenue des Martyrs, CS 40220, Grenoble, 38043, France; Department of Chemistry, KU Leuven, Celestijnenlaan 200F box 2404, 3001, Leuven, Belgium
| | - Sarah A Brady
- DCU Biomaterials Research Group, Centre for Medical Engineering Research, School of Mechanical and Manufacturing Engineering, Dublin City University, Dublin 9, Ireland
| | - Eoin K Fox
- DCU Biomaterials Research Group, Centre for Medical Engineering Research, School of Mechanical and Manufacturing Engineering, Dublin City University, Dublin 9, Ireland
| | - Caitríona Lally
- Department of Mechanical and Manufacturing Engineering, School of Engineering and Trinity Centre for Bioengineering, Trinity College Dublin, Dublin 2, Ireland
| |
Collapse
|
20
|
Using a Chemical Genetic Screen to Enhance Our Understanding of the Antimicrobial Properties of Gallium against Escherichia coli. Genes (Basel) 2019; 10:genes10010034. [PMID: 30634525 PMCID: PMC6356860 DOI: 10.3390/genes10010034] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 12/17/2018] [Accepted: 01/04/2019] [Indexed: 12/13/2022] Open
Abstract
The diagnostic and therapeutic agent gallium offers multiple clinical and commercial uses including the treatment of cancer and the localization of tumors, among others. Further, this metal has been proven to be an effective antimicrobial agent against a number of microbes. Despite the latter, the fundamental mechanisms of gallium action have yet to be fully identified and understood. To further the development of this antimicrobial, it is imperative that we understand the mechanisms by which gallium interacts with cells. As a result, we screened the Escherichia coli Keio mutant collection as a means of identifying the genes that are implicated in prolonged gallium toxicity or resistance and mapped their biological processes to their respective cellular system. We discovered that the deletion of genes functioning in response to oxidative stress, DNA or iron–sulfur cluster repair, and nucleotide biosynthesis were sensitive to gallium, while Ga resistance comprised of genes involved in iron/siderophore import, amino acid biosynthesis and cell envelope maintenance. Altogether, our explanations of these findings offer further insight into the mechanisms of gallium toxicity and resistance in E. coli.
Collapse
|
21
|
Wakamatsu T, Morono Y, Futagami T, Terada T, Nishikawa S, Morisawa T, Ohshita K, Inagaki F, Ashiuchi M. Metal-ion-induced expression of gene fragments from subseafloor micro-organisms in the Kumano forearc basin, Nankai Trough. J Appl Microbiol 2018; 125:1396-1407. [PMID: 30080957 DOI: 10.1111/jam.14061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 06/30/2018] [Accepted: 07/23/2018] [Indexed: 12/30/2022]
Abstract
AIMS Using substrate-induced gene-expression (SIGEX) screening on subseafloor sediment samples from the Nankai Trough, Japan, we identified gene fragments showing an induction response to metal ions. METHODS AND RESULTS Environmental DNA libraries in Escherichia coli host cells were tested by the addition of metal ions (Ni2+ , Co2+ , Ga3+ or Mo6+ ), followed by cell sorting of clones exhibiting green fluorescence upon co-expression of green fluorescence protein downstream of the inserted gene fragments. One clone displayed Ni2+ -specific induction, three clones displayed Ga3+ -specific induction and three clones displayed an induction response to multiple metal ions. DNA sequence analysis showed that a variety of genes showed induction responses in the screened clones. CONCLUSIONS Using the SIGEX approach, we retrieved gene fragments with no previously identified response to metal ions that exhibited metal-ion-induced expression. This method has the potential to promote exploration of gene function through gene-induction response. SIGNIFICANCE AND IMPACT OF THE STUDY We successfully linked gene-induction response with sequence information for gene fragments of previously unknown function. The SIGEX-based approach exhibited the potential to identify genetic function in unknown gene pools from the deep subseafloor biosphere, as well as novel genetic components for future biotechnological applications.
Collapse
Affiliation(s)
- T Wakamatsu
- Agricultural Science, Graduate School of Integrated Arts and Sciences, Kochi University, Kochi, Japan
| | - Y Morono
- Geomicrobiology Group, Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Kochi, Japan.,Geobiotechnology Group, Research and Development Center for Submarine Resources, JAMSTEC, Kanagawa, Japan
| | - T Futagami
- Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima, Japan
| | - T Terada
- Marine Works Japan Ltd, Kanagawa, Japan
| | - S Nishikawa
- Agricultural Science, Graduate School of Integrated Arts and Sciences, Kochi University, Kochi, Japan
| | - T Morisawa
- Agricultural Science, Graduate School of Integrated Arts and Sciences, Kochi University, Kochi, Japan
| | - K Ohshita
- Agricultural Science, Graduate School of Integrated Arts and Sciences, Kochi University, Kochi, Japan
| | - F Inagaki
- Geomicrobiology Group, Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Kochi, Japan.,Geobiotechnology Group, Research and Development Center for Submarine Resources, JAMSTEC, Kanagawa, Japan.,Research and Development Center for Ocean Drilling Science, Kanagawa, Japan
| | - M Ashiuchi
- Agricultural Science, Graduate School of Integrated Arts and Sciences, Kochi University, Kochi, Japan
| |
Collapse
|
22
|
Chalker J, Gardiner D, Kuksal N, Mailloux RJ. Characterization of the impact of glutaredoxin-2 (GRX2) deficiency on superoxide/hydrogen peroxide release from cardiac and liver mitochondria. Redox Biol 2018; 15:216-227. [PMID: 29274570 PMCID: PMC5773472 DOI: 10.1016/j.redox.2017.12.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 12/07/2017] [Accepted: 12/13/2017] [Indexed: 01/30/2023] Open
Abstract
Mitochondria are critical sources of hydrogen peroxide (H2O2), an important secondary messenger in mammalian cells. Recent work has shown that O2•-/H2O2 emission from individual sites of production in mitochondria is regulated by protein S-glutathionylation. Here, we conducted the first examination of O2•-/H2O2 release rates from cardiac and liver mitochondria isolated from mice deficient for glutaredoxin-2 (GRX2), a matrix-associated thiol oxidoreductase that facilitates the S-glutathionylation and deglutathionylation of proteins. Liver mitochondria isolated from mice heterozygous (GRX2+/-) and homozygous (GRX2-/-) for glutaredoxin-2 displayed a significant decrease in O2•-/H2O2 release when oxidizing pyruvate or 2-oxoglutarate. The genetic deletion of the Grx2 gene was associated with increased protein expression of pyruvate dehydrogenase (PDH) but not 2-oxoglutarate dehydrogenase (OGDH). By contrast, O2•-/H2O2 production was augmented in cardiac mitochondria from GRX2+/- and GRX2-/- mice metabolizing pyruvate or 2-oxoglutarate which was associated with decreased PDH and OGDH protein levels. ROS production was augmented in liver and cardiac mitochondria metabolizing succinate. Inhibitor studies revealed that OGDH and Complex III served as high capacity ROS release sites in liver mitochondria. By contrast, Complex I and Complex III were found to be the chief O2•-/H2O2 emitters in cardiac mitochondria. These findings identify an essential role for GRX2 in regulating O2•-/H2O2 release from mitochondria in liver and cardiac tissue. Our results demonstrate that the GRX2-mediated regulation of O2•-/H2O2 release through the S-glutathionylation of mitochondrial proteins may play an integral role in controlling cellular ROS signaling.
Collapse
Affiliation(s)
- Julia Chalker
- Memorial University of Newfoundland, Department of Biochemistry, St. John's, Newfoundland, Canada
| | - Danielle Gardiner
- Memorial University of Newfoundland, Department of Biochemistry, St. John's, Newfoundland, Canada
| | - Nidhi Kuksal
- Memorial University of Newfoundland, Department of Biochemistry, St. John's, Newfoundland, Canada
| | - Ryan J Mailloux
- Memorial University of Newfoundland, Department of Biochemistry, St. John's, Newfoundland, Canada.
| |
Collapse
|
23
|
Role and mechanism of the AMPK pathway in waterborne Zn exposure influencing the hepatic energy metabolism of Synechogobius hasta. Sci Rep 2016; 6:38716. [PMID: 27934965 PMCID: PMC5146659 DOI: 10.1038/srep38716] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 11/15/2016] [Indexed: 12/18/2022] Open
Abstract
Previous studies have investigated the physiological responses in the liver of Synechogobius hasta exposed to waterborne zinc (Zn). However, at present, very little is known about the underlying molecular mechanisms of these responses. In this study, RNA sequencing (RNA-seq) was performed to analyse the differences in the hepatic transcriptomes between control and Zn-exposed S. hasta. A total of 36,339 unigenes and 1,615 bp of unigene N50 were detected. These genes were further annotated to the Nonredundant protein (NR), Nonredundant nucleotide (Nt), Swiss-Prot, Kyoto Encyclopedia of Genes and Genomes (KEGG), Clusters of Orthologous Groups (COG) and Gene Ontology (GO) databases. After 60 days of Zn exposure, 708 and 237 genes were significantly up- and down-regulated, respectively. Many differentially expressed genes (DEGs) involved in energy metabolic pathways were identified, and their expression profiles suggested increased catabolic processes and reduced biosynthetic processes. These changes indicated that waterborne Zn exposure increased the energy production and requirement, which was related to the activation of the AMPK signalling pathway. Furthermore, using the primary hepatocytes of S. hasta, we identified the role of the AMPK signalling pathway in Zn-influenced energy metabolism.
Collapse
|
24
|
Kurtjak M, Vukomanović M, Kramer L, Suvorov D. Biocompatible nano-gallium/hydroxyapatite nanocomposite with antimicrobial activity. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2016; 27:170. [PMID: 27704374 DOI: 10.1007/s10856-016-5777-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Accepted: 09/02/2016] [Indexed: 06/06/2023]
Abstract
Intensive research in the area of medical nanotechnology, especially to cope with the bacterial resistance against conventional antibiotics, has shown strong antimicrobial action of metallic and metal-oxide nanomaterials towards a wide variety of bacteria. However, the important remaining problem is that nanomaterials with highest antibacterial activity generally express also a high level of cytotoxicity for mammalian cells. Here we present gallium nanoparticles as a new solution to this problem. We developed a nanocomposite from bioactive hydroxyapatite nanorods (84 wt %) and antibacterial nanospheres of elemental gallium (16 wt %) with mode diameter of 22 ± 11 nm. In direct comparison, such nanocomposite with gallium nanoparticles exhibited better antibacterial properties against Pseudomonas aeruginosa and lower in-vitro cytotoxicity for human lung fibroblasts IMR-90 and mouse fibroblasts L929 (efficient antibacterial action and low toxicity from 0.1 to 1 g/L) than the nanocomposite of hydroxyapatite and silver nanoparticles (efficient antibacterial action and low toxicity from 0.2 to 0.25 g/L). This is the first report of a biomaterial composite with gallium nanoparticles. The observed strong antibacterial properties and low cytotoxicity make the investigated material promising for the prevention of implantation-induced infections that are frequently caused by P. aeruginosa.
Collapse
Affiliation(s)
- Mario Kurtjak
- Jožef Stefan Institute, Advanced Materials Department, Jamova cesta 39, Ljubljana, 1000, Slovenia.
- Jozef Stefan International Postgraduate School, Jamova cesta 39, Ljubljana, 1000, Slovenia.
| | - Marija Vukomanović
- Jožef Stefan Institute, Advanced Materials Department, Jamova cesta 39, Ljubljana, 1000, Slovenia
| | - Lovro Kramer
- Jozef Stefan International Postgraduate School, Jamova cesta 39, Ljubljana, 1000, Slovenia
- Jožef Stefan Institute, Department of Biochemistry and Molecular Biology, Jamova cesta 39, Ljubljana, 1000, Slovenia
| | - Danilo Suvorov
- Jožef Stefan Institute, Advanced Materials Department, Jamova cesta 39, Ljubljana, 1000, Slovenia
| |
Collapse
|
25
|
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.
Collapse
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.
| |
Collapse
|
26
|
Restoration of growth by manganese in a mutant strain of Escherichia coli lacking most known iron and manganese uptake systems. Biometals 2016; 29:433-50. [PMID: 27003826 DOI: 10.1007/s10534-016-9927-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Accepted: 03/14/2016] [Indexed: 10/22/2022]
Abstract
The interplay of manganese and iron homeostasis and oxidative stress in Escherichia coli can give important insights into survival of bacteria in the phagosome and under differing iron or manganese bioavailabilities. Here, we characterized a mutant strain devoid of all know iron/manganese-uptake systems relevant for growth in defined medium. Based on these results an exit strategy enabling the cell to cope with iron depletion and use of manganese as an alternative for iron could be shown. Such a strategy would also explain why E. coli harbors some iron- or manganese-dependent iso-enzymes such as superoxide dismutases or ribonucleotide reductases. The benefits for gaining a means for survival would be bought with the cost of less efficient metabolism as indicated in our experiments by lower cell densities with manganese than with iron. In addition, this strain was extremely sensitive to the metalloid gallium but this gallium toxicity can be alleviated by low concentrations of manganese.
Collapse
|
27
|
Monitoring of an antigen manufacturing process. Bioprocess Biosyst Eng 2016; 39:855-69. [DOI: 10.1007/s00449-016-1565-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 02/04/2016] [Indexed: 01/09/2023]
|
28
|
Alhasawi A, Thomas SC, Appanna VD. Metabolic networks to generate pyruvate, PEP and ATP from glycerol in Pseudomonas fluorescens. Enzyme Microb Technol 2016; 85:51-6. [PMID: 26920481 DOI: 10.1016/j.enzmictec.2016.01.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 01/07/2016] [Accepted: 01/15/2016] [Indexed: 01/02/2023]
Abstract
Glycerol is a major by-product of the biodiesel industry. In this study we report on the metabolic networks involved in its transformation into pyruvate, phosphoenolpyruvate (PEP) and ATP. When the nutritionally-versatile Pseudomonas fluorescens was exposed to hydrogen peroxide (H2O2) in a mineral medium with glycerol as the sole carbon source, the microbe reconfigured its metabolism to generate adenosine triphosphate (ATP) primarily via substrate-level phosphorylation (SLP). This alternative ATP-producing stratagem resulted in the synthesis of copious amounts of PEP and pyruvate. The production of these metabolites was mediated via the enhanced activities of such enzymes as pyruvate carboxylase (PC) and phosphoenolpyruvate carboxylase (PEPC). The high energy PEP was subsequently converted into ATP with the aid of pyruvate phosphate dikinase (PPDK), phosphoenolpyruvate synthase (PEPS) and pyruvate kinase (PK) with the concomitant formation of pyruvate. The participation of the phospho-transfer enzymes like adenylate kinase (AK) and acetate kinase (ACK) ensured the efficiency of this O2-independent energy-generating machinery. The increased activity of glycerol dehydrogenase (GDH) in the stressed bacteria provided the necessary precursors to fuel this process. This H2O2-induced anaerobic life-style fortuitously evokes metabolic networks to an effective pathway that can be harnessed into the synthesis of ATP, PEP and pyruvate. The bioconversion of glycerol to pyruvate will offer interesting economic benefit.
Collapse
Affiliation(s)
- Azhar Alhasawi
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON P3E2C6, Canada
| | - Sean C Thomas
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON P3E2C6, Canada
| | - Vasu D Appanna
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON P3E2C6, Canada.
| |
Collapse
|
29
|
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.
Collapse
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.
| |
Collapse
|
30
|
Auger C, Appanna ND, Alhasawi A, Appanna VD. Deciphering metabolic networks by blue native polyacrylamide gel electrophoresis: A functional proteomic exploration. EUPA OPEN PROTEOMICS 2015. [DOI: 10.1016/j.euprot.2015.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
31
|
Sandoval JM, Arenas FA, García JA, Díaz-Vásquez WA, Valdivia-González M, Sabotier M, Vásquez CC. Escherichia coli 6-phosphogluconate dehydrogenase aids in tellurite resistance by reducing the toxicant in a NADPH-dependent manner. Microbiol Res 2015. [PMID: 26211962 DOI: 10.1016/j.micres.2015.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Exposure to the tellurium oxyanion tellurite (TeO3(2-)) results in the establishment of an oxidative stress status in most microorganisms. Usually, bacteria growing in the presence of the toxicant turn black because of the reduction of tellurite (Te(4+)) to the less-toxic elemental tellurium (Te(0)). In vitro, at least part of tellurite reduction occurs enzymatically in a nicotinamide dinucleotide-dependent reaction. In this work, we show that TeO3(2-) reduction by crude extracts of Escherichia coli overexpressing the zwf gene (encoding glucose-6-phosphate dehydrogenase) takes place preferentially in the presence of NADPH instead of NADH. The enzyme responsible for toxicant reduction was identified as 6-phosphogluconate dehydrogenase (Gnd). The gnd gene showed a subtle induction at short times after toxicant exposure while strains lacking gnd were more susceptible to the toxicant. These results suggest that both NADPH-generating enzymes from the pentose phosphate shunt may be involved in tellurite detoxification and resistance in E. coli.
Collapse
Affiliation(s)
- J M Sandoval
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - F A Arenas
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - J A García
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - W A Díaz-Vásquez
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile; Facultad de Ciencias de la Salud, Universidad San Sebastián, Santiago, Chile
| | - M Valdivia-González
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - M Sabotier
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - C C Vásquez
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile.
| |
Collapse
|
32
|
Rangel-Vega A, Bernstein LR, Mandujano-Tinoco EA, García-Contreras SJ, García-Contreras R. Drug repurposing as an alternative for the treatment of recalcitrant bacterial infections. Front Microbiol 2015; 6:282. [PMID: 25914685 PMCID: PMC4391038 DOI: 10.3389/fmicb.2015.00282] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 03/21/2015] [Indexed: 01/17/2023] Open
Abstract
Bacterial infection remains one of the leading causes of death worldwide, and the options for treating such infections are decreasing, due the rise of antibiotic-resistant bacteria. The pharmaceutical industry has produced few new types of antibiotics in more than a decade. Researchers are taking several approaches toward developing new classes of antibiotics, including (1) focusing on new targets and processes, such as bacterial cell–cell communication that upregulates virulence; (2) designing inhibitors of bacterial resistance, such as blockers of multidrug efflux pumps; and (3) using alternative antimicrobials such as bacteriophages. In addition, the strategy of finding new uses for existing drugs is beginning to produce results: antibacterial properties have been discovered for existing anticancer, antifungal, anthelmintic, and anti-inflammatory drugs. In this review, we discuss the antimicrobial properties of gallium compounds, 5-fluorouracil, ciclopirox, diflunisal, and some other FDA-approved drugs and argue that their repurposing for the treatment of bacterial infections, including those that are multidrug resistant, is a feasible strategy.
Collapse
Affiliation(s)
- Adrián Rangel-Vega
- Department of Microbiology and Parasitology, Faculty of Medicine, Universidad Nacional Autónoma de México Mexico City, Mexico
| | | | - Edna Ayerim Mandujano-Tinoco
- Epigenetics of Cancer Laboratory, Division of Basic Research, National Institute of Genomic Medicine Mexico City, Mexico
| | | | - Rodolfo García-Contreras
- Department of Microbiology and Parasitology, Faculty of Medicine, Universidad Nacional Autónoma de México Mexico City, Mexico
| |
Collapse
|
33
|
Alhasawi A, Costanzi J, Auger C, Appanna ND, Appanna VD. Metabolic reconfigurations aimed at the detoxification of a multi-metal stress in Pseudomonas fluorescens: implications for the bioremediation of metal pollutants. J Biotechnol 2015; 200:38-43. [PMID: 25724118 DOI: 10.1016/j.jbiotec.2015.01.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 01/29/2015] [Accepted: 01/31/2015] [Indexed: 01/09/2023]
Abstract
Although the ability of microbial systems to adapt to the toxic challenge posed by numerous metal pollutants individually has been well documented, there is little detailed information on how bacteria survive in a multiple-metal environment. Here we describe the metabolic reconfiguration invoked by the soil microbe Pseudomonas fluorescens in a medium with millimolar amounts of aluminum (Al), iron (Fe), gallium (Ga), calcium (Ca), and zinc (Zn). While enzymes involved in the production of NADH were decreased, there was a marked increase in enzymatic activities dedicated to NADPH formation. A modified tricarboxylic acid (TCA) cycle coupled to an alternate glyoxylate shunt mediated the synthesis of adenosine triphosphate (ATP) with the concomitant generation of oxalate. This dicarboxylic acid was a key ingredient in the sequestration of the metals that were detoxified as a lipid complex. It appears that the microbe favors this strategy as opposed to a detoxification process aimed at each metal separately. These findings have interesting implications for bioremediation technologies.
Collapse
Affiliation(s)
- Azhar Alhasawi
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON, Canada
| | - Jacob Costanzi
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON, Canada
| | - Christopher Auger
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON, Canada
| | - Nishma D Appanna
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON, Canada
| | - Vasu D Appanna
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON, Canada.
| |
Collapse
|
34
|
Alhasawi A, Castonguay Z, Appanna ND, Auger C, Appanna VD. Glycine metabolism and anti-oxidative defence mechanisms in Pseudomonas fluorescens. Microbiol Res 2015; 171:26-31. [PMID: 25644949 DOI: 10.1016/j.micres.2014.12.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Revised: 11/25/2014] [Accepted: 12/07/2014] [Indexed: 12/22/2022]
Abstract
The role of metabolism in anti-oxidative defence is only now beginning to emerge. Here, we show that the nutritionally-versatile microbe, Pseudomonas fluorescens, reconfigures its metabolism in an effort to generate NADPH, ATP and glyoxylate in order to fend off oxidative stress. Glyoxylate was produced predominantly via the enhanced activities of glycine dehydrogenase-NADP(+) (GDH), glycine transaminase (GTA) and isocitrate lyase (ICL) in a medium exposed to hydrogen peroxide (H₂O₂). This ketoacid was utilized to produce ATP by substrate-level phosphorylation and to neutralize reactive oxygen species with the concomitant formation of formate. The latter was also a source of NADPH, a process mediated by formate dehydrogenase-NADP(+) (FDH). The increased activities of phosphoenolpyruvate carboxylase (PEPC) and pyruvate orthophosphate dikinase (PPDK) worked in tandem to synthesize ATP in the H₂O₂-challenged cells that had markedly diminished capacity for oxidative phosphorylation. These metabolic networks provide an effective means of combating ROS and reveal therapeutic targets against microbes resistant to oxidative stress.
Collapse
Affiliation(s)
- Azhar Alhasawi
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON, Canada
| | - Zachary Castonguay
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON, Canada
| | - Nishma D Appanna
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON, Canada
| | - Christopher Auger
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON, Canada
| | - Vasu D Appanna
- Faculty of Science and Engineering, Laurentian University, Sudbury, ON, Canada.
| |
Collapse
|
35
|
Alhasawi A, Auger C, Appanna VP, Chahma M, Appanna VD. Zinc toxicity and ATP production in Pseudomonas fluorescens. J Appl Microbiol 2014; 117:65-73. [PMID: 24629129 DOI: 10.1111/jam.12497] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 02/28/2014] [Accepted: 03/08/2014] [Indexed: 01/15/2023]
Abstract
AIMS To identify the molecular networks in Pseudomonas fluorescens that convey resistance to toxic concentrations of Zn, a common pollutant and hazard to biological systems. METHODS AND RESULTS Pseudomonas fluorescens strain ATCC 13525 was cultured in growth medium with millimolar concentrations of Zn. Enzymatic activities and metabolite levels were monitored with the aid of in-gel activity assays and high-performance liquid chromatography, respectively. As oxidative phosphorylation was rendered ineffective, the assimilation of citric acid mediated sequentially by citrate lyase (CL), phosphoenolpyruvate carboxylase (PEPC) and pyruvate phosphate dikinase (PPDK) appeared to play a key role in ATP synthesis via substrate-level phosphorylation (SLP). Enzymes generating the antioxidant, reduced nicotinamide adenine dinucleotide phosphate (NADPH) were enhanced, while metabolic modules mediating the formation of the pro-oxidant, reduced nicotinamide adenine dinucleotide (NADH) were downregulated. CONCLUSIONS Pseudomonas fluorescens reengineers its metabolic networks to generate ATP via SLP, a stratagem that allows the microbe to compensate for an ineffective electron transport chain provoked by excess Zn. SIGNIFICANCE AND IMPACT OF THE STUDY The molecular insights described here are critical in devising strategies to bioremediate Zn-polluted environments.
Collapse
Affiliation(s)
- A Alhasawi
- Department Chemistry & Biochemistry, Laurentian University, Sudbury, ON, Canada
| | | | | | | | | |
Collapse
|
36
|
Minandri F, Bonchi C, Frangipani E, Imperi F, Visca P. Promises and failures of gallium as an antibacterial agent. Future Microbiol 2014; 9:379-97. [DOI: 10.2217/fmb.14.3] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
|
37
|
Bignucolo A, Appanna VP, Thomas SC, Auger C, Han S, Omri A, Appanna VD. Hydrogen peroxide stress provokes a metabolic reprogramming in Pseudomonas fluorescens: enhanced production of pyruvate. J Biotechnol 2013; 167:309-15. [PMID: 23871654 DOI: 10.1016/j.jbiotec.2013.07.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 06/28/2013] [Accepted: 07/02/2013] [Indexed: 10/26/2022]
Abstract
Pseudomonas fluorescens invoked a metabolic reconfiguration that resulted in enhanced production of pyruvate under the challenge of hydrogen peroxide (H₂O₂). Although this stress led to a sharp reduction in the activities of numerous tricarboxylic acid (TCA) cycle enzymes, there was a marked increase in the activities of catalase and various NADPH-generating enzymes to counter the oxidative burden. The upregulation of phosphoenolpyruvate synthase (PEPS) and pyruvate kinase (PK) coupled with the reduction of pyruvate dehydrogenase (PDH) in the H₂O₂-challenged cells appear to be important contributors to the elevated levels of pyruvate found in these bacteria. Increased pyruvate synthesis was evident in the presence of a variety of carbon sources including d-glucose. Intact cells rapidly consumed d-glucose with the concomitant formation of this monocarboxylic acid. At least a 12-fold increase in pyruvate production within 1h was observed in the stressed cells. These findings may be exploited in the development of technologies aimed at the conversion of carbohydrates into pyruvate.
Collapse
Affiliation(s)
- Adam Bignucolo
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6, Canada
| | | | | | | | | | | | | |
Collapse
|
38
|
Auger C, Han S, Appanna VP, Thomas SC, Ulibarri G, Appanna VD. Metabolic reengineering invoked by microbial systems to decontaminate aluminum: implications for bioremediation technologies. Biotechnol Adv 2012. [PMID: 23201464 DOI: 10.1016/j.biotechadv.2012.11.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
As our reliance on aluminum (Al) increases, so too does its presence in the environment and living systems. Although generally recognized as safe, its interactions with most living systems have been nefarious. This review presents an overview of the noxious effects of Al and how a subset of microbes can rework their metabolic pathways in order to survive an Al-contaminated environment. For instance, in order to expulse the metal as an insoluble precipitate, Pseudomonas fluorescens shuttles metabolites toward the production of organic acids and lipids that play key roles in chelating, immobilizing and exuding Al. Further, the reconfiguration of metabolic modules enables the microorganism to combat the dearth of iron (Fe) and the excess of reactive oxygen species (ROS) promoted by Al toxicity. While in Rhizobium spp., exopolysaccharides have been invoked to sequester this metal, an ATPase is known to safeguard Anoxybacillus gonensis against the trivalent metal. Hydroxyl, carboxyl and phosphate moieties have also been exploited by microbes to trap Al. Hence, an understanding of the metabolic networks that are operative in microorganisms residing in polluted environments is critical in devising bioremediation technologies aimed at managing metal wastes. Metabolic engineering is essential in elaborating effective biotechnological processes to decontaminate metal-polluted surroundings.
Collapse
Affiliation(s)
- Christopher Auger
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada P3E 2C6
| | | | | | | | | | | |
Collapse
|
39
|
Han S, Auger C, Castonguay Z, Appanna VP, Thomas SC, Appanna VD. The unravelling of metabolic dysfunctions linked to metal-associated diseases by blue native polyacrylamide gel electrophoresis. Anal Bioanal Chem 2012; 405:1821-31. [PMID: 23001308 DOI: 10.1007/s00216-012-6413-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 09/01/2012] [Accepted: 09/05/2012] [Indexed: 01/18/2023]
Abstract
Gel electrophoresis is routinely used to separate and analyse macromolecules in biological systems. Although many of these electrophoretic techniques necessitate the denaturing of the analytes prior to their analysis, blue native polyacrylamide gel electrophoresis (BN-PAGE) permits the investigation of proteins/enzymes and their supramolecular structures such as the metabolon in native form. This attribute renders this analytical tool conducive to deciphering the metabolic perturbations invoked by metal toxicity. In this review, we elaborate on how BN-PAGE has led to the discovery of the dysfunctional metabolic pathways associated with disorders such as Alzheimer's disease, Parkinson's disease, and obesity that have been observed as a consequence of exposure to various metal toxicants.
Collapse
Affiliation(s)
- Sungwon Han
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON P3E 2C6, Canada
| | | | | | | | | | | |
Collapse
|
40
|
Lant B, Storey KB. Glucose-6-Phosphate Dehydrogenase Regulation in Anoxia Tolerance of the Freshwater Crayfish Orconectes virilis. Enzyme Res 2011; 2011:524906. [PMID: 22013511 PMCID: PMC3195688 DOI: 10.4061/2011/524906] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 08/10/2011] [Indexed: 11/20/2022] Open
Abstract
Glucose-6-phosphate dehydrogenase (G6PDH), the enzyme which catalyzes the rate determining step of the pentose phosphate pathway (PPP), controls the production of nucleotide precursor molecules (R5P) and powerful reducing molecules (NADPH) that support multiple biosynthetic functions, including antioxidant defense. G6PDH from hepatopancreas of the freshwater crayfish (Orconectes virilis) showed distinct kinetic changes in response to 20 h anoxic exposure. K(m) values for both substrates decreased significantly in anoxic crayfish; K(m) NADP(+) dropped from 0.015 ± 0.008 mM to 0.012 ± 0.008 mM, and K(m) G6P decreased from 0.13 ± 0.02 mM to 0.08 ± 0.007 mM. Two lines of evidence indicate that the mechanism involved is reversible phosphorylation. In vitro incubations that stimulated protein kinase or protein phosphatase action mimicked the effects on anoxia on K(m) values, whereas DEAE-Sephadex chromatography showed the presence of two enzyme forms (low- and high-phosphate) whose proportions changed during anoxia. Incubation studies implicated protein kinase A and G in mediating the anoxia-responsive changes in G6PDH kinetic properties. In addition, the amount of G6PDH protein (measured by immunoblotting) increased by ∼60% in anoxic hepatopancreas. Anoxia-induced phosphorylation of G6PDH could contribute to modifying carbon flow through the PPP under anoxic conditions, potentially maintaining NADPH supply for antioxidant defense during prolonged anoxia-induced hypometabolism.
Collapse
Affiliation(s)
- Benjamin Lant
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada K1S 5B6
| | | |
Collapse
|
41
|
Sandoval JM, Arenas FA, Vásquez CC. Glucose-6-phosphate dehydrogenase protects Escherichia coli from tellurite-mediated oxidative stress. PLoS One 2011; 6:e25573. [PMID: 21984934 PMCID: PMC3184162 DOI: 10.1371/journal.pone.0025573] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Accepted: 09/07/2011] [Indexed: 11/27/2022] Open
Abstract
The tellurium oxyanion tellurite induces oxidative stress in most microorganisms. In Escherichia coli, tellurite exposure results in high levels of oxidized proteins and membrane lipid peroxides, inactivation of oxidation-sensitive enzymes and reduced glutathione content. In this work, we show that tellurite-exposed E. coli exhibits transcriptional activation of the zwf gene, encoding glucose 6-phosphate dehydrogenase (G6PDH), which in turn results in augmented synthesis of reduced nicotinamide adenine dinucleotide phosphate (NADPH). Increased zwf transcription under tellurite stress results mainly from reactive oxygen species (ROS) generation and not from a depletion of cellular glutathione. In addition, the observed increase of G6PDH activity was paralleled by accumulation of glucose-6-phosphate (G6P), suggesting a metabolic flux shift toward the pentose phosphate shunt. Upon zwf overexpression, bacterial cells also show increased levels of antioxidant molecules (NADPH, GSH), better-protected oxidation-sensitive enzymes and decreased amounts of oxidized proteins and membrane lipids. These results suggest that by increasing NADPH content, G6PDH plays an important role in E. coli survival under tellurite stress.
Collapse
Affiliation(s)
- Juan M. Sandoval
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - Felipe A. Arenas
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - Claudio C. Vásquez
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| |
Collapse
|
42
|
Decorosi F, Lori L, Santopolo L, Tatti E, Giovannetti L, Viti C. Characterization of a Cr(VI)-sensitive Pseudomonas corrugata 28 mutant impaired in a pyridine nucleotide transhydrogenase gene. Res Microbiol 2011; 162:747-55. [PMID: 21807093 DOI: 10.1016/j.resmic.2011.06.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Accepted: 06/23/2011] [Indexed: 11/29/2022]
Abstract
Bacteria are known to adopt complex metabolic strategies in an effort to counteract the impact of numerous toxic compounds. In this study, a Cr(VI)-sensitive mutant of the Cr(VI)-hyperresistant bacterium Pseudomonas corrugata 28, obtained by insertional mutagenesis using the EZ-Tn5™ <R6Kγori/KAN-2>Tnp, was employed to gain a greater understanding of Cr(VI) resistance in bacteria. The insertion of the transposon, which occurred 16 bp upstream from the start codon of an ORF encoding a soluble pyridine nucleotide transhydrogenase (STH), negatively affected expression of the sth gene. The compromised expression of the sth gene in the mutant had two main effects on the pyridine nucleotide pools: (i) a decrease in NADPH and NADH fractions with a consequent shift in the redox state toward oxidation; and (ii) a decrease in the total concentration of the pyridine nucleotides. In the absence of a suitable pool of NADPH, the mutant failed to sustain an effective defense against the oxidative stress induced by Cr(VI).
Collapse
Affiliation(s)
- Francesca Decorosi
- Dipartimento di Biotecnologie Agrarie, Sezione di Microbiologia and Laboratorio Genexpress, Università degli Studi di Firenze, Piazzale delle Cascine, 24, I-50144 Florence, Italy
| | | | | | | | | | | |
Collapse
|
43
|
Booth SC, Workentine ML, Wen J, Shaykhutdinov R, Vogel HJ, Ceri H, Turner RJ, Weljie AM. Differences in metabolism between the biofilm and planktonic response to metal stress. J Proteome Res 2011; 10:3190-9. [PMID: 21561166 DOI: 10.1021/pr2002353] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Bacterial biofilms are known to withstand the effects of toxic metals better than planktonic cultures of the same species. This phenomenon has been attributed to many features of the sessile lifestyle not present in free-swimming populations, but the contribution of intracellular metabolism has not been previously examined. Here, we use a combined GC-MS and (1)H NMR metabolomic approach to quantify whole-cell metabolism in biofilm and planktonic cultures of the multimetal resistant bacterium Pseudomonas fluorescens exposed to copper ions. Metabolic changes in response to metal exposure were found to be significantly different in biofilms compared to planktonic cultures. Planktonic metabolism indicated an oxidative stress response that was characterized by changes to the TCA cycle, glycolysis, pyruvate and nicotinate and niacotinamide metabolism. Similar metabolic changes were not observed in biofilms, which were instead dominated by shifts in exopolysaccharide related metabolism suggesting that metal stress in biofilms induces a protective response rather than the reactive changes observed for the planktonic cells. From these results, we conclude that differential metabolic shifts play a role in biofilm-specific multimetal resistance and tolerance. An altered metabolic response to metal toxicity represents a novel addition to a growing list of biofilm-specific mechanisms to resist environmental stress.
Collapse
Affiliation(s)
- Sean C Booth
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada T2N 1N4
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Metabolic networks to combat oxidative stress in Pseudomonas fluorescens. Antonie van Leeuwenhoek 2010; 99:433-42. [PMID: 21153706 DOI: 10.1007/s10482-010-9538-x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Accepted: 11/26/2010] [Indexed: 12/21/2022]
Abstract
Oxidative stress is an unavoidable peril that aerobic organisms have to confront. Thus, it is not surprising that intricate strategies are deployed in an effort to fend the dangers associated with living in an O(2) environment. In the classical models of anti-oxidative defense mechanisms, a variety of stratagems including the reactive oxygen species (ROS) scavenging systems, the NADPH-generating enzymes and the DNA repair machineries are highlighted. However, it is becoming increasingly clear that metabolism may be intimately involved in anti-oxidative defence. Recent data show that metabolic reprogramming plays a pivotal role in the survival of organisms exposed to oxidative stress. Here, we describe how Pseudomonas fluorescens, the metabolically-versatile soil microbe, manipulates its metabolic networks in an effort to counter oxidative stress. An intricate link between metabolism and anti-oxidative defense is presented. P. fluorescens reconfigures its metabolic processes in an effort to satisfy its need for NADPH during oxidative insult. Seemingly, disparate metabolic modules appear to partner together to concomitantly fine-tune the levels of the anti-oxidant NADPH and the pro-oxidant NADH. Central to this shift in the metabolic production of the pyridine nucleotides is the increase in NAD kinase with the concomitant decrease in NADP phosphatase. The tricarboxylic acid cycle is tweaked in an effort to limit the formation of NADH. This metabolic redox-balancing act appears to afford a potent tool against oxidative challenge and may be a more widespread ROS-combating tactic than hitherto recognized.
Collapse
|
45
|
Lemire J, Mailloux R, Auger C, Whalen D, Appanna VD. Pseudomonas fluorescens orchestrates a fine metabolic-balancing act to counter aluminium toxicity. Environ Microbiol 2010; 12:1384-90. [PMID: 20353438 DOI: 10.1111/j.1462-2920.2010.02200.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Aluminium (Al), an environmental toxin, is known to disrupt cellular functions by perturbing iron (Fe) homeostasis. However, Fe is essential for such metabolic processes as the tricarboxylic acid (TCA) cycle and oxidative phosphorylation, the two pivotal networks that mediate ATP production during aerobiosis. To counter the Fe conundrum induced by Al toxicity, Pseudomonas fluorescens utilizes isocitrate lyase and isocitrate dehydrogenase-NADP dependent to metabolize citrate when confronted with an ineffective aconitase provoked by Al stress. By invoking fumarase C, a hydratase devoid of Fe, this microbe is able to generate essential metabolites. To compensate for the severely diminished enzymes like Complex I, Complex II and Complex IV, the upregulation of a H(2)O-generating NADH oxidase enables the metabolism of citrate, the sole carbon source via a modified TCA cycle. The overexpression of succinyl-CoA synthetase affords an effective route to ATP production by substrate-level phosphorylation in the absence of O(2). This fine metabolic balance enables P. fluorescens to survive the dearth of bioavailable Fe triggered by an Al environment, a feature that may have potential applications in bioremediation technologies.
Collapse
Affiliation(s)
- Joseph Lemire
- Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON, Canada, P3E 2C6
| | | | | | | | | |
Collapse
|
46
|
Walton RC, White KN, Livens F, McCrohan CR. The suitability of gallium as a substitute for aluminum in tracing experiments. Biometals 2009; 23:221-30. [DOI: 10.1007/s10534-009-9280-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Accepted: 11/18/2009] [Indexed: 10/20/2022]
|
47
|
Involvement of fumarase C and NADH oxidase in metabolic adaptation of Pseudomonas fluorescens cells evoked by aluminum and gallium toxicity. Appl Environ Microbiol 2008; 74:3977-84. [PMID: 18469122 DOI: 10.1128/aem.02702-07] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Iron (Fe) is a critical element in all aerobic organisms as it participates in a variety of metabolic networks. In this study, aluminum (Al) and gallium (Ga), two Fe mimetics, severely impeded the ability of the soil microbe Pseudomonas fluorescens to perform oxidative phosphorylation. This was achieved by disrupting the activity and expression of complexes I, II, and IV. These toxic metals also inactivated aconitase (ACN) and fumarase A (FUM A), two tricarboxylic acid cycle enzymes dependent on Fe for their catalytic activity, while FUM C, an Fe-independent enzyme, displayed an increase in activity and expression under these stressed situations. Furthermore, in the Al- and Ga-exposed cells, the activity and expression of an H(2)O-forming NADH oxidase were markedly increased. The incubation of the Al- and Ga-challenged cells in an Fe-containing medium led to the recovery of the affected enzymatic activities. Taken together, these data provide novel insights into how environmental pollutants such as Al and Ga interfere with cellular Fe metabolism and also illustrate the ability of Pseudomonas fluorescens to modulate metabolic networks to combat this situation.
Collapse
|
48
|
Lemire J, Mailloux R, Appanna VD. Zinc toxicity alters mitochondrial metabolism and leads to decreased ATP production in hepatocytes. J Appl Toxicol 2008; 28:175-82. [PMID: 17582580 DOI: 10.1002/jat.1263] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Although zinc (Zn) is a known environmental toxicant, its impact on the cellular energy-producing machinery is not well established. This study investigated the influence of this divalent metal on the oxidative ATP producing network in human hepatocellular carcinoma (HepG2) cells. Zn-challenged cells contained more oxidized proteins and lipids compared with control cells. Zn severely impeded mitochondrial functions by inhibiting aconitase, alpha-ketoglutarate dehydrogenase, isocitrate dehydrogenase-NAD+ dependent, succinate dehydrogenase and cytochrome C oxidase Zn-exposed cells had a disparate mitochondrial metabolism compared with the control cells and produced significantly less ATP. However, the expression of isocitrate dehydrogenase-NADP+ dependent was more prominent in cells treated with Zn. Hence, Zn-induced pathologies may be due to the inability of the mitochondria to generate energy effectively.
Collapse
Affiliation(s)
- Joseph Lemire
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6, Canada
| | | | | |
Collapse
|
49
|
Effects of zinc supplementation on antioxidant enzyme activities in healthy old subjects. Exp Gerontol 2008; 43:445-51. [DOI: 10.1016/j.exger.2007.10.012] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2007] [Revised: 10/16/2007] [Accepted: 10/23/2007] [Indexed: 01/22/2023]
|