Enhanced glycolysis and GSK3 inactivation promote brain metabolic adaptations following neuronal mitochondrial stress

Abstract We analyzed early brain metabolic adaptations in response to mitochondrial dysfunction in a mouse model of mitochondrial encephalopathy with complex IV deficiency (neuron specific COX10 KO). In this mouse model the onset of the mitochondrial defect did not coincide with immediate cell death suggesting early adaptive metabolic responses to compensate for the energetic deficit. Metabolomic analysis in the knockout mice revealed increased levels of glycolytic and pentose phosphate pathway intermediates, amino acids and lysolipids. Glycolysis was modulated by enhanced activity of glycolytic enzymes, and not by their overexpression, suggesting the importance of post-translational modifications in the adaptive response. GSK3 inactivation was the most upstream regulation identified, implying that it is a key event in this adaptive mechanism. Because neurons are thought not to rely on glycolysis for ATP production in normal conditions, our results indicate that neurons still maintain their ability to upregulate this pathway when under mitochondrial respiration stress.

Download Full-text

Biochemical and Proteomic Changes in the Roots of M4 Grapevine Rootstock in Response to Nitrate Availability

Plants ◽

10.3390/plants10040792 ◽

2021 ◽

Vol 10 (4) ◽

pp. 792

Author(s):

Bhakti Prinsi ◽

Chiara Muratore ◽

Luca Espen

Keyword(s):

Amino Acid ◽

Time Course ◽

Agricultural Soils ◽

Pentose Phosphate ◽

Post Translational Modifications ◽

Hydroponic System ◽

N Nutrition ◽

Metabolic Adaptations ◽

Nitrate Availability ◽

Amino Acid Contents

In agricultural soils, nitrate (NO3−) is the major nitrogen (N) nutrient for plants, but few studies have analyzed molecular and biochemical responses involved in its acquisition by grapevine roots. In viticulture, considering grafting, NO3− acquisition is strictly dependent on rootstock. To improve the knowledge about N nutrition in grapevine, this study analyzed biochemical and proteomic changes induced by, NO3− availability, in a hydroponic system, in the roots of M4, a recently selected grapevine rootstock. The evaluation of biochemical parameters, such as NO3−, sugar and amino acid contents in roots, and the abundance of nitrate reductase, allowed us to define the time course of the metabolic adaptations to NO3− supply. On the basis of these results, the proteomic analysis was conducted by comparing the root profiles in N-starved plants and after 30 h of NO3− resupply. The analysis quantified 461 proteins, 26% of which differed in abundance between conditions. Overall, this approach highlighted, together with an increased N assimilatory metabolism, a concomitant rise in the oxidative pentose phosphate pathway and glycolysis, needed to fulfill the redox power and carbon skeleton demands, respectively. Moreover, a wide modulation of protein and amino acid metabolisms and changes of proteins involved in root development were observed. Finally, some results open new questions about the importance of redox-related post-translational modifications and of NO3− availability in modulating the dialog between root and rhizosphere.

Download Full-text

Cinnamon Oil Inhibits Penicillium expansum Growth by Disturbing the Carbohydrate Metabolic Process

Journal of Fungi ◽

10.3390/jof7020123 ◽

2021 ◽

Vol 7 (2) ◽

pp. 123

Author(s):

Tongfei Lai ◽

Yangying Sun ◽

Yaoyao Liu ◽

Ran Li ◽

Yuanzhi Chen ◽

...

Keyword(s):

Pentose Phosphate ◽

Metabolic Process ◽

Penicillium Expansum ◽

Economic Losses ◽

Pome Fruit ◽

Cinnamon Oil ◽

Atp Production ◽

Protein Levels ◽

Regulatory Enzymes ◽

Expression Of Genes

Penicillium expansum is a major postharvest pathogen that mainly threatens the global pome fruit industry and causes great economic losses annually. In the present study, the antifungal effects and potential mechanism of cinnamon oil against P. expansum were investigated. Results indicated that 0.25 mg L−1 cinnamon oil could efficiently inhibit the spore germination, conidial production, mycelial accumulation, and expansion of P. expansum. In addition, it could effectively control blue mold rots induced by P. expansum in apples. Cinnamon oil could also reduce the expression of genes involved in patulin biosynthesis. Through a proteomic quantitative analysis, a total of 146 differentially expressed proteins (DEPs) involved in the carbohydrate metabolic process, most of which were down-regulated, were noticed for their large number and functional significance. Meanwhile, the expressions of 14 candidate genes corresponding to DEPs and the activities of six key regulatory enzymes (involving in cellulose hydrolyzation, Krebs circle, glycolysis, and pentose phosphate pathway) showed a similar trend in protein levels. In addition, extracellular carbohydrate consumption, intracellular carbohydrate accumulation, and ATP production of P. expansum under cinnamon oil stress were significantly decreased. Basing on the correlated and mutually authenticated results, we speculated that disturbing the fungal carbohydrate metabolic process would be partly responsible for the inhibitory effects of cinnamon oil on P. expansum growth. The findings would provide new insights into the antimicrobial mode of cinnamon oil.

Download Full-text

How N-Acetylcysteine Supplementation Affects Redox Regulation, Especially at Mitohormesis and Sarcohormesis Level: Current Perspective

Antioxidants ◽

10.3390/antiox10020153 ◽

2021 ◽

Vol 10 (2) ◽

pp. 153

Author(s):

Aslı Devrim-Lanpir ◽

Lee Hill ◽

Beat Knechtle

Keyword(s):

Oxidative Stress ◽

Oxidative Metabolism ◽

Adaptive Response ◽

Redox Regulation ◽

Therapeutic Agent ◽

Metabolic Effects ◽

Metabolic Adaptations ◽

Current Perspective ◽

Exercise Induced ◽

Response To Exercise

Exercise frequently alters the metabolic processes of oxidative metabolism in athletes, including exposure to extreme reactive oxygen species impairing exercise performance. Therefore, both researchers and athletes have been consistently investigating the possible strategies to improve metabolic adaptations to exercise-induced oxidative stress. N-acetylcysteine (NAC) has been applied as a therapeutic agent in treating many diseases in humans due to its precursory role in the production of hepatic glutathione, a natural antioxidant. Several studies have investigated NAC’s possible therapeutic role in oxidative metabolism and adaptive response to exercise in the athletic population. However, still conflicting questions regarding NAC supplementation need to be clarified. This narrative review aims to re-evaluate the metabolic effects of NAC on exercise-induced oxidative stress and adaptive response developed by athletes against the exercise, especially mitohormetic and sarcohormetic response.

Download Full-text

TMOD-24. GENERATION AND CHARACTERIZATION OF A NOVEL TRANSGENIC IDO REPORTER MOUSE FOR IDO POSTTRANSLATIONAL MODIFICATION ANALYSIS IN SITU

Neuro-Oncology ◽

10.1093/neuonc/noaa215.974 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii233-ii233

Author(s):

April Bell ◽

Lijie Zhai ◽

Erik Ladomersky ◽

Kristen Lauing ◽

Lakshmi Bollu ◽

...

Keyword(s):

Mouse Model ◽

Tumor Cell ◽

Central Nervous System Tumor ◽

Post Translational Modifications ◽

Reporter Mouse ◽

C Terminus ◽

Human Gbm

Abstract Glioblastoma (GBM) is the most common and aggressive primary central nervous system tumor in adults with a median survival of 14.6 months. GBM is a potently immunosuppressive cancer due in-part to the prolific expression of immunosuppressive indoleamine 2,3 dioxygenase 1 (IDO). Tumor cell IDO facilitates the intratumoral accumulation of regulatory T cells (Tregs; CD4+CD25+FoxP3+). Although immunosuppressive IDO activity is canonically characterized by the conversion of tryptophan into kynurenine, we have utilized transgenic and syngeneic mouse models and mutant glioma lines to demonstrate that tumor cell IDO increases Treg accumulation independent of tryptophan metabolism. Here, we address the gap in our understanding of IDO signaling activity in vivo. Subcutaneously-engrafted human GBM expressing human IDO-GFP cDNA was isolated from immunodeficient humanized NSG-SGM3 mice. The tumor was immunoprecipitated for the GFP tag using GFP-TRAP followed by mass spectrometry which revealed a novel methylation site on a lysine residue at amino acid 373 in the IDO C-terminus region. Western blot analysis of IDO protein also revealed the presence of tyrosine phosphorylation. Additionally, we recently created a new transgenic IDO reporter mouse model whereby endogenous IDO is fused to GFP via a T2A linker (IDO→GFP). This model allows for the isolation of IDO+ cells in real-time and without causing cell death, thereby creating the opportunity for downstream molecular analysis of in situ-isolated GFP+ cells. Collectively, our work suggests that IDO non-enzyme activity may involve the post-translational modifications we recently identified. As IDO activity may differ between in vitro and in vivo modeling systems, we will use the new IDO→GFP reporter mouse model for an improved mechanistic understanding of how immunosuppressive IDO facilitates Treg accumulation in vivo.

Download Full-text

Multiplatform metabolomic analysis of the R6/2 mouse model of Huntington’s disease

FEBS Open Bio ◽

10.1002/2211-5463.13285 ◽

2021 ◽

Author(s):

Masayo Hashimoto ◽

Kenichi Watanabe ◽

Kan Miyoshi ◽

Yukako Koyanagi ◽

Jun Tadano ◽

...

Keyword(s):

Mouse Model ◽

Huntington's Disease ◽

Huntington’S Disease ◽

Metabolomic Analysis

Download Full-text

Cell-Wide Survey of Amide-Bonded Lysine Modifications by Using Deacetylase CobB

Biological Procedures Online ◽

10.1186/s12575-019-0109-x ◽

2019 ◽

Vol 21 (1) ◽

Author(s):

Yun Wei ◽

Wan-Jie Yang ◽

Qi-Jun Wang ◽

Peng-Cheng Lin ◽

Jian-Yuan Zhao ◽

...

Keyword(s):

Mass Spectrometry ◽

Gas Chromatography ◽

Protein Function ◽

Gas Chromatography Mass Spectrometry ◽

Human Tissues ◽

Metabolomic Analysis ◽

Dynamic Changes ◽

Post Translational Modifications ◽

Covalently Bonded ◽

Different Origins

Abstract Background Lysine post-translational modifications are important regulators of protein function. Proteomic and biochemical approaches have resulted in identification of several lysine modifications, including acetylation, crotonylation, and succinylation. Here, we developed an approach for surveying amide-bonded lysine modifications in the proteome of human tissues/cells based on the observation that many lysine modifications are amide-bonded and that the Salmonella enterica deacetylase, CobB, is an amidase. Results After the proteome of human tissues/cells was denatured and the non-covalently bonded metabolites were removed by acetone washes, and the amide-bonded modifiers were released by CobB and analyzed using liquid- and/or gas chromatography/mass spectrometry metabolomic analysis. This protocol, which required 3–4 days for completion, was used to qualitatively identify more than 40 documented and unreported lysine modifications from the human proteome and to quantitatively analyze dynamic changes in targeted amide-bonded lysine modifications. Conclusions We developed a method that was capable of monitoring and quantifying amide-bonded lysine modifications in cells of different origins.

Download Full-text

Time-resolved metabolomics analysis of β-cells implicates the pentose phosphate pathway in the control of insulin release

Biochemical Journal ◽

10.1042/bj20121349 ◽

2013 ◽

Vol 450 (3) ◽

pp. 595-605 ◽

Cited By ~ 48

Author(s):

Peter Spégel ◽

Vladimir V. Sharoyko ◽

Isabel Goehring ◽

Anders P. H. Danielsson ◽

Siri Malmgren ◽

...

Keyword(s):

Insulin Secretion ◽

Pentose Phosphate Pathway ◽

Metabolic Response ◽

Cell Metabolism ◽

Pentose Phosphate ◽

Β Cells ◽

Β Cell ◽

Time Resolved ◽

Atp Production ◽

Rat Islets

Insulin secretion is coupled with changes in β-cell metabolism. To define this process, 195 putative metabolites, mitochondrial respiration, NADP+, NADPH and insulin secretion were measured within 15 min of stimulation of clonal INS-1 832/13 β-cells with glucose. Rapid responses in the major metabolic pathways of glucose occurred, involving several previously suggested metabolic coupling factors. The complexity of metabolite changes observed disagreed with the concept of one single metabolite controlling insulin secretion. The complex alterations in metabolite levels suggest that a coupling signal should reflect large parts of the β-cell metabolic response. This was fulfilled by the NADPH/NADP+ ratio, which was elevated (8-fold; P<0.01) at 6 min after glucose stimulation. The NADPH/NADP+ ratio paralleled an increase in ribose 5-phosphate (>2.5-fold; P<0.001). Inhibition of the pentose phosphate pathway by trans-dehydroepiandrosterone (DHEA) suppressed ribose 5-phosphate levels and production of reduced glutathione, as well as insulin secretion in INS-1 832/13 β-cells and rat islets without affecting ATP production. Metabolite profiling of rat islets confirmed the glucose-induced rise in ribose 5-phosphate, which was prevented by DHEA. These findings implicate the pentose phosphate pathway, and support a role for NADPH and glutathione, in β-cell stimulus-secretion coupling.

Download Full-text

Impaired Pentose Phosphate Pathway in the Spinal Cord of the hSOD1G93A Mouse Model of Amyotrophic Lateral Sclerosis

Molecular Neurobiology ◽

10.1007/s12035-019-1485-6 ◽

2019 ◽

Vol 56 (8) ◽

pp. 5844-5855 ◽

Cited By ~ 6

Author(s):

Tesfaye Wolde Tefera ◽

Katherine Bartlett ◽

Shirley S. Tran ◽

Mark P. Hodson ◽

Karin Borges

Keyword(s):

Spinal Cord ◽

Amyotrophic Lateral Sclerosis ◽

Mouse Model ◽

Pentose Phosphate Pathway ◽

Pentose Phosphate ◽

Lateral Sclerosis

Download Full-text

Brain Glucose Metabolism: Integration of Energetics with Function

Physiological Reviews ◽

10.1152/physrev.00062.2017 ◽

2019 ◽

Vol 99 (1) ◽

pp. 949-1045 ◽

Cited By ~ 88

Author(s):

Gerald A. Dienel

Keyword(s):

Aerobic Glycolysis ◽

Local Level ◽

Nutritional Therapy ◽

Brain Regions ◽

Pentose Phosphate ◽

Atp Production ◽

Cellular Energetics ◽

Excitatory Neurotransmission ◽

Evaluation Of Data ◽

Glycogen Turnover

Glucose is the long-established, obligatory fuel for brain that fulfills many critical functions, including ATP production, oxidative stress management, and synthesis of neurotransmitters, neuromodulators, and structural components. Neuronal glucose oxidation exceeds that in astrocytes, but both rates increase in direct proportion to excitatory neurotransmission; signaling and metabolism are closely coupled at the local level. Exact details of neuron–astrocyte glutamate–glutamine cycling remain to be established, and the specific roles of glucose and lactate in the cellular energetics of these processes are debated. Glycolysis is preferentially upregulated during brain activation even though oxygen availability is sufficient (aerobic glycolysis). Three major pathways, glycolysis, pentose phosphate shunt, and glycogen turnover, contribute to utilization of glucose in excess of oxygen, and adrenergic regulation of aerobic glycolysis draws attention to astrocytic metabolism, particularly glycogen turnover, which has a high impact on the oxygen–carbohydrate mismatch. Aerobic glycolysis is proposed to be predominant in young children and specific brain regions, but re-evaluation of data is necessary. Shuttling of glucose- and glycogen-derived lactate from astrocytes to neurons during activation, neurotransmission, and memory consolidation are controversial topics for which alternative mechanisms are proposed. Nutritional therapy and vagus nerve stimulation are translational bridges from metabolism to clinical treatment of diverse brain disorders.

Download Full-text

Combined metabolome and transcriptome analysis reveals key components of complete desiccation tolerance in an anhydrobiotic insect

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2003650117 ◽

2020 ◽

Vol 117 (32) ◽

pp. 19209-19220 ◽

Cited By ~ 1

Author(s):

Alina Ryabova ◽

Richard Cornette ◽

Alexander Cherkasov ◽

Masahiko Watanabe ◽

Takashi Okuda ◽

...

Keyword(s):

Transcriptome Analysis ◽

Molecular Mechanisms ◽

Adenosine Monophosphate ◽

Pentose Phosphate ◽

Toxic Waste ◽

Mitochondrial Activity ◽

Xanthurenic Acid ◽

Metabolic Adaptations ◽

Polypedilum Vanderplanki ◽

Protective Proteins

Some organisms have evolved a survival strategy to withstand severe dehydration in an ametabolic state, called anhydrobiosis. The only known example of anhydrobiosis among insects is observed in larvae of the chironomidPolypedilum vanderplanki. Recent studies have led to a better understanding of the molecular mechanisms underlying anhydrobiosis and the action of specific protective proteins. However, gene regulation alone cannot explain the rapid biochemical reactions and independent metabolic changes that are expected to sustain anhydrobiosis. For this reason, we conducted a comprehensive comparative metabolome–transcriptome analysis in the larvae. We showed that anhydrobiotic larvae adopt a unique metabolic strategy to cope with complete desiccation and, in particular, to allow recovery after rehydration. We argue that trehalose, previously known for its anhydroprotective properties, plays additional vital roles, providing both the principal source of energy and also the restoration of antioxidant potential via the pentose phosphate pathway during the early stages of rehydration. Thus, larval viability might be directly dependent on the total amount of carbohydrate (glycogen and trehalose). Furthermore, in the anhydrobiotic state, energy is stored as accumulated citrate and adenosine monophosphate, allowing rapid reactivation of the citric acid cycle and mitochondrial activity immediately after rehydration, before glycolysis is fully functional. Other specific adaptations to desiccation include potential antioxidants (e.g., ophthalmic acid) and measures to avoid the accumulation of toxic waste metabolites by converting these to stable and inert counterparts (e.g., xanthurenic acid and allantoin). Finally, we confirmed that these metabolic adaptations correlate with unique organization and expression of the corresponding enzyme genes.

Download Full-text