DJ-1 family Maillard deglycases prevent acrylamide formation

The Tale of DJ-1 (PARK7): A Swiss Army Knife in Biomedical and Psychological Research

DJ-1 (also known as PARK7) is a multifunctional enzyme in human beings that is highly conserved and that has also been discovered in diverse species (ranging from prokaryotes to eukaryotes). Its complex enzymatic and non-enzymatic activities (such as anti-oxidation, anti-glycation, and protein quality control), as well as its role as a transcriptional coactivator, enable DJ-1 to serve as an essential regulator in multiple cellular processes (e.g., epigenetic regulations) and make it a promising therapeutic target for diverse diseases (especially cancer and Parkinson's disease). Due to its nature as a Swiss army knife enzyme with various functions, DJ-1 has attracted a large amount of research interest, from different perspectives. In this review, we give a brief summary of the recent advances with respect to DJ-1 research in biomedicine and psychology, as well as the progress made in attempts to develop DJ-1 into a druggable target for therapy.

Molecular imprinting technology and poly (ionic liquid)s: Promising tools with industrial application for the removal of acrylamide and furanic compounds from coffee and other foods

Coffee is one of the most consumed beverages in the world. Coffee provides to the consumer special sensorial characteristics, can help to prevent diseases, improves physical performance and increases focus. In contrast, coffee consumption supplies a significant source of substances with carcinogenic and genotoxic potential such as furan, hydroxymethylfurfural (HMF), furfural (F), and acrylamide (AA). The present review addresses the issues around the presence of such toxic substances formed in Maillard reaction (MR) during thermal treatments in food processing, from chemical and, toxicological perspectives, occurrences in coffee and other foods processed by heating. In addition, current strategies advantages and disadvantages are presented along with application of molecular imprinting technology (MIT) and poly (ionic liquid) s (PIL) as an alternative to reduce the furan, HMF, F and AA content in coffee and other foods.

Parkinson's disease protein PARK7 prevents metabolite and protein damage caused by a glycolytic metabolite

Reactive compounds cause cellular damage that is suspected to contribute to aging and neurodegenerative diseases. Oxidative stress and environmental factors likely contribute to this. Here we report that an enzyme mutated in Parkinson’s disease can prevent damage of metabolites and proteins caused by a metabolite from the central pathway of sugar metabolism. Inactivation of this enzyme in model systems, ranging from flies to human cells, leads to the accumulation of a wide range of damaged metabolites and proteins. Thus, this enzyme represents a highly conserved strategy to prevent damage in cells that metabolize sugars. Overall, we discovered a fundamental link between carbohydrate metabolism and a type of cellular damage that might contribute to the development of Parkinson’s disease.

Cells are continuously exposed to potentially dangerous compounds. Progressive accumulation of damage is suspected to contribute to neurodegenerative diseases and aging, but the molecular identity of the damage remains largely unknown. Here we report that PARK7, an enzyme mutated in hereditary Parkinson’s disease, prevents damage of proteins and metabolites caused by a metabolite of glycolysis. We found that the glycolytic metabolite 1,3-bisphosphoglycerate (1,3-BPG) spontaneously forms a novel reactive intermediate that avidly reacts with amino groups. PARK7 acts by destroying this intermediate, thereby preventing the formation of proteins and metabolites with glycerate and phosphoglycerate modifications on amino groups. As a consequence, inactivation of PARK7 (or its orthologs) in human cell lines, mouse brain, and Drosophila melanogaster leads to the accumulation of these damaged compounds, most of which have not been described before. Our work demonstrates that PARK7 function represents a highly conserved strategy to prevent damage in cells that metabolize carbohydrates. This represents a fundamental link between metabolism and a type of cellular damage that might contribute to the development of Parkinson’s disease.

The C terminus of DJ-1 determines its homodimerization, MGO detoxification activity and suppression of ferroptosis

DJ-1 is a multifunctional protein associated with cancers and autosomal early-onset Parkinson disease. Besides the well-documented antioxidative stress activity, recent studies show that DJ-1 has deglycation enzymatic activity and anti-ferroptosis effect. It has been shown that DJ-1 forms the homodimerization, which dictates its antioxidative stress activity. In this study, we investigated the relationship between the dimeric structure of DJ-1 and its newly reported activities. In HEK293T cells with Flag-tagged and Myc-tagged DJ-1 overexpression, we performed deletion mutations and point mutations, narrowed down the most critical motif at the C terminus. We found that the deletion mutation of the last three amino acids at the C terminus of DJ-1 (DJ-1 ΔC3) disrupted its homodimerization with the hydrophobic L187 residue being of great importance for DJ-1 homodimerization. In addition, the ability in methylglyoxal (MGO) detoxification and deglycation was almost abolished in the mutation of DJ-1 ΔC3 and point mutant L187E compared with wild-type DJ-1 (DJ-1 WT). We also showed the suppression of erastin-triggered ferroptosis in DJ-1-/- mouse embryonic fibroblast cells was abolished by ΔC3 and L187E, but partially diminished by V51C. Thus, our results demonstrate that the C terminus of DJ-1 is crucial for its homodimerization, deglycation activity, and suppression of ferroptosis.

Cytoprotective Mechanisms of DJ-1: Implications in Cardiac Pathophysiology

DJ-1 was originally identified as an oncogene product while mutations of the gene encoding DJ-1/PARK7 were later associated with a recessive form of Parkinson's disease. Its ubiquitous expression and diversity of function suggest that DJ-1 is also involved in mechanisms outside the central nervous system. In the last decade, the contribution of DJ-1 to the protection from ischemia-reperfusion injury has been recognized and its involvement in the pathophysiology of cardiovascular disease is attracting increasing attention. This review describes the current and gaps in our knowledge of DJ-1, focusing on its role in regulating cardiovascular function. In parallel, we present original data showing an association between increased DJ-1 expression and antiapoptotic and anti-inflammatory markers following cardiac and vascular surgical procedures. Future studies should address DJ-1's role as a plausible novel therapeutic target for cardiovascular disease.

Antioxidative activity of oyster protein hydrolysates Maillard reaction products

A two-step process of enzymatic hydrolyzation followed by Maillard reaction was used to produce oyster meat hydrolysate Maillard reaction products (MRPs). The flavor of oyster meat hydrolysate MRPs was significantly improved through an optimized orthogonal experimental design. Comparisons between the antioxidative activities of oyster meat hydrolysates and their MRPs were made using lipid peroxidation inhabitation, hydroxyl radical scavenging radical activity, and radical scavenging activity of 2,2 diphenyl-1-picrylhydrazyl (DPPH). These methods indicated that an improvement of Maillard reaction on the oyster meat hydrolysates antioxidative activity. Gas chromatography-mass spectrometry illustrated that the increase was due to the newly formed antioxidative compounds after Maillard reaction, mainly of acids from 22.45% to 37.77% and phenols from 0% to 9.88%.

Sensory attribute and antioxidant capacity of Maillard reaction products from enzymatic hydrolysate of bovine bone marrow extract

Abstract

Maillard reaction and Maillard reaction products (MRPs) are commonly used in food industry, with various sensory and functional properties. Bovine bone marrow extract (BBME) was subjected to enzymatic hydrolysis, followed by the Maillard reaction to enhance its sensory attributes. The antioxidant and antihypertensive activities of BBME, its hydrolysate and their MRPs were assessed. (3⁷) orthogonal experimental design was used to obtain the optimal reaction conditions for generation of MRPs with improved sensory characteristics. The optimal conditions were: processing temperature, 120 °C; processing time, 60 min; xylose concentration, 2.5% (w/v); cysteine concentration, 2%; Vitamin B1, 1.2%; Hydrolyzed vegetable protein, 6%; and sample to liquid ratio, 1:1. The total content of free amino acid in BBME decreased from 86.18 to 25.50 g L^-1 in EH-BBME-MRPs. In addition, EH-BBME and EH-BBME-MRPs contained significantly higher amount of low molecular weight peptides (< 1000 Da; 47.2% and 21.84%, respectively) compared to other samples. They also exhibited enhanced antioxidant activities against DPPH, ABTS and hydroxyl free radicals, and presented improved FRAP activity and reducing power. EH-BBME-MRPs also exhibited higher antihypertensive activity compared to other samples. The results indicate that MRPs derived from BBME hydrolysate are promising components for improving food flavor and also provide health benefits.

Graphic abstract

Effects of Formulation and Baking Process on Acrylamide Formation in Kolompeh, a Traditional Cookie in Iran

Thermal treatments and recipes are two critical aspects for the formation of acrylamide at ordinary household cooking conditions and industrial level. Kolompeh is a traditional Iranian cookie, and the aim of this study was to monitor acrylamide formation in four different recipes: traditional sugary Kolompeh (TSK), traditional simple Kolompeh (TSIK), industrial sugary Kolompeh (ISK), and industrial simple Kolompeh (ISIK). Along with the measurement of reducing sugars, moisture, and pH, acrylamide was quantified by gas chromatography mass spectrometry (GC-MS). Results indicated that acrylamide content was 1758, 1048, 888, and 560 μg/kg for TSK, TSIK, ISK, and ISIK, respectively, revealing that the kind of thermal treatment in combination with higher concentrations of reducing sugars were the major driver for acrylamide formation. In particular, acrylamide concentration in TSIK direct heating was 1.87 times higher than industrial indirect heating treatment, highlighting that domestic preparation of Kolompeh required a specific attention as a source of potential toxic molecule formation.

Bifunctional Chloroplastic DJ-1B from Arabidopsis thaliana is an Oxidation-Robust Holdase and a Glyoxalase Sensitive to H₂O₂

Members of the DJ-1 protein family are multifunctional enzymes whose loss increases the susceptibility of the cell to oxidative stress. However, little is known about the function of the plant DJ-1 homologs. Therefore, we analyzed the effect of oxidation on the structure and function of chloroplastic AtDJ-1B and studied the phenotype of T-DNA lines lacking the protein. In vitro oxidation of AtDJ-1B with H₂O₂ lowers its glyoxalase activity, but has no effect on its holdase chaperone function. Remarkably, upon oxidation, the thermostability of AtDJ-1B increases with no significant alteration of the overall secondary structure. Moreover, we found that AtDJ-1B transcript levels are invariable, and loss of AtDJ-1B does not affect plant viability, growth and stress response. All in all, two discrete functions of AtDJ-1B respond differently to H₂O₂, and AtDJ-1B is not essential for plant development under stress.

Further characterization of the Maillard deglycase DJ-1 and its prokaryotic homologs, deglycase 1/Hsp31, deglycase 2/YhbO, and deglycase 3/YajL

We reported recently that the Parkinsonism-associated protein DJ-1 and its bacterial homologs Hsp31, YhbO and YajL function as deglycases that repair proteins and nucleotides from endogeneous glycation by glyoxal and methylglyoxal, two reactive by-products of glucose metabolism responsible for up to 60% of glycation damage. Here, we show that DJ-1, deglycase 1 and deglycase 2 repair glyoxal- and methylglyoxal-glycated substrates, whereas deglycase 3 principally repairs glyoxal-glycated substrates. Moreover, deglycase 1 and 2 are overexpressed in stationary phase, whereas deglycase 3 is steadily expressed throughout bacterial growth. Finally, deglycase mutants overexpress glyoxalases, aldoketoreductases, glutathione-S-transferase and efflux pumps to alleviate carbonyl stress. In the discussion, we present an overview of the multiple functions of DJ-1 proteins. Our thourough work on deglycases provides compelling evidence that their previously reported glyoxalase III activity merely reflects their deglycase activity. Moreover, for their deglycase activity the Maillard deglycases likely recruit: i) their chaperone activity to interact with glycated proteins, ii) glyoxalase 1 activity to catalyze the rearrangement of Maillard products (aminocarbinols and hemithioacetals) into amides and thioesters, respectively, iii) their protease activity to cleave amide bonds of glycated arginine, lysine and guanine, and iv) glyoxalase 2 activity to cleave thioester bonds of glycated cysteine. Finally, because glycation affects many cellular processes, the discovery of the Maillard deglycases, awaited since 1912, likely constitutes a major advance for medical research, including ageing, cancer, atherosclerosis, neurodegenerative, post-diabetic, renal and autoimmune diseases.

Emerging fields in chaperone proteins: A French workshop

The "Bioénergétique et Ingénierie des Protéines (BIP)" laboratory, CNRS (France), organized its first French workshop on molecular chaperone proteins and protein folding in November 2017. The goal of this workshop was to gather scientists working in France on chaperone proteins and protein folding. This initiative was a great success with excellent talks and fruitful discussions. The highlights were on the description of unexpected functions and post-translational regulation of known molecular chaperones (such as Hsp90, Hsp33, SecB, GroEL) and on state-of-the-art methods to tackle questions related to this theme, including Cryo-electron microscopy, Nuclear Magnetic Resonance (NMR), Electron Paramagnetic Resonance (EPR), simulation and modeling. We expect to organize a second workshop in two years that will include more scientists working in France in the chaperone field.

Metabolite damage and repair in metabolic engineering design

The necessarily sharp focus of metabolic engineering and metabolic synthetic biology on pathways and their fluxes has tended to divert attention from the damaging enzymatic and chemical side-reactions that pathway metabolites can undergo. Although historically overlooked and underappreciated, such metabolite damage reactions are now known to occur throughout metabolism and to generate (formerly enigmatic) peaks detected in metabolomics datasets. It is also now known that metabolite damage is often countered by dedicated repair enzymes that undo or prevent it. Metabolite damage and repair are highly relevant to engineered pathway design: metabolite damage reactions can reduce flux rates and product yields, and repair enzymes can provide robust, host-independent solutions. Herein, after introducing the core principles of metabolite damage and repair, we use case histories to document how damage and repair processes affect efficient operation of engineered pathways - particularly those that are heterologous, non-natural, or cell-free. We then review how metabolite damage reactions can be predicted, how repair reactions can be prospected, and how metabolite damage and repair can be built into genome-scale metabolic models. Lastly, we propose a versatile 'plug and play' set of well-characterized metabolite repair enzymes to solve metabolite damage problems known or likely to occur in metabolic engineering and synthetic biology projects.

Bacterial Responses to Glyoxal and Methylglyoxal: Reactive Electrophilic Species

Glyoxal (GO) and methylglyoxal (MG), belonging to α-oxoaldehydes, are produced by organisms from bacteria to humans by glucose oxidation, lipid peroxidation, and DNA oxidation. Since glyoxals contain two adjacent reactive carbonyl groups, they are referred to as reactive electrophilic species (RES), and are damaging to proteins and nucleotides. Therefore, glyoxals cause various diseases in humans, such as diabetes and neurodegenerative diseases, from which all living organisms need to be protected. Although the glyoxalase system has been known for some time, details on how glyoxals are sensed and detoxified in the cell have not been fully elucidated, and are only beginning to be uncovered. In this review, we will summarize the current knowledge on bacterial responses to glyoxal, and specifically focus on the glyoxal-associated regulators YqhC and NemR, as well as their detoxification mediated by glutathione (GSH)-dependent/independent glyoxalases and NAD(P)H-dependent reductases. Furthermore, we will address questions and future directions.

Protein Repair from Glycation by Glyoxals by the DJ-1 Family Maillard Deglycases

DJ-1 and its prokaryotic homologs, Hsp31, YhbO and YajL from Escherichia coli and PfpI from Pyrococcus furiosus, repair proteins from glycation by glyoxals (R-CO-CHO), which constitute their major glycating agents. Glycation is a non-enzymatic covalent reaction discovered by Louis Camille Maillard in 1912, between reactive carbonyls (reducing sugars and glyoxals) and amino acids (cysteine, arginine and lysine), which inactivates proteins. By degrading Maillard adducts formed between carbonyls and thiols or amino groups, the DJ-1 family Maillard deglycases prevent the formation of the so-called advanced glycation end products (AGEs) that arise from Maillard adducts after dehydrations, oxidations and rearrangements. Since glycation is involved in ageing, cancer, atherosclerosis and cataracts, as well as post-diabetic, neurovegetatives and renal and autoimmune diseases, the DJ-1 deglycases are likely to play an important role in preventing these diseases. These deglycases, especially those from thermophilic organisms, may also be used to prevent the formation of dietary AGEs during food processing, sterilization and storage. They also prevent acrylamide formation in food, likely by degrading the asparagine/glyoxal Maillard adducts responsible for its formation. Since Maillard adducts are the substrates of the DJ-1 family deglycases, we propose renaming them Maillard deglycases.

Parkinsonism-associated protein DJ-1 is a bona fide deglycase

We discovered recently that Parkinsonism-associated DJ-1 and its bacterial homologs function as protein deglycases that repair glyoxal- and methylglyoxal-glycated proteins. Protein glycation levels are 2- to 10-fold increased in deglycase-depleted cells, and deglycase mutants display up to 500-fold loss of viability in methylglyoxal or glucose-containing media, suggesting that these deglycases play important roles in protecting cells against electrophile and carbonyl stress. Although the deglycase activity of DJ-1 is well supported by extensive biochemical work, Pfaff et al. (J. Biol. Chem. in presshttp://dx.doi.org/10.1074/jbc.M116.743823) claimed in a recent study that deglycation of the hemithioacetal formed upon cysteine glycation by methylglyoxal results from a Tris buffer artefact. Here, we show that this is not the case, and that DJ-1 and its homologs are the bona fide deglycases awaited since the Maillard discovery.