PCIS1, encoded by a pentatricopeptide protein co-expressed gene, is required for splicing of three mitochondrial nad transcripts in angiosperms.

Group II introns are large catalytic RNAs, which reside mainly within genes encoding respiratory complex I (CI) subunits in angiosperms' mitochondria. Genetic and biochemical analyses led to the identification of many nuclear-encoded factors that facilitate the splicing of the degenerated organellar introns in plants. Here, we describe the analysis of the PPR Co-expressed Intron Splicing1 (PCIS1) factor, which was identified in-silico by its co-expression pattern with many PPR proteins. PCIS1 is well conserved in land plants but has no sequence similarity with any known protein motifs. PCIS1 mutant lines are arrested in embryogenesis and can be maintained by the temporal expression of the gene under the embryo-specific ABI3 promoter. The pABI3::PCIS1 mutant plants display low germination and stunted growth phenotypes. RNA-seq and RT-qPCR analyses of wild type and mutant plants indicated that PCIS1 is a novel splicing cofactor that is pivotal for the maturation of several nad transcripts in Arabidopsis mitochondria. These phenotypes are tightly associated with respiratory complex I defects and altered plant growth. Our data further emphasizes the key roles of nuclear-encoded cofactors that regulate the maturation and expression of mitochondrial transcripts for the biogenesis of the oxidative phosphorylation (OXPHOS) system, and hence for plant physiology. The discovery of novel splicing factors other than typical RNA-binding proteins suggests further complexity of splicing mechanisms in plant mitochondria.

NMRK2 is an efficient diagnostic indicator for Xp11.2 translocation renal cell carcinoma.

Xp11.2 translocation renal cell carcinomas (tRCC) are a rare and highly malignant type of renal cancer, lacking efficient diagnostic indicators and therapeutic targets. Through the analysis of public databases and our cohort, we identified NMRK2 as a potential diagnostic marker for distinguishing Xp11.2 tRCC from kidney renal clear cell carcinoma (KIRC) and kidney renal papillary cell carcinoma (KIRP) due to its specific upregulation in Xp11.2 tRCC tissues. Mechanistically, we discovered that TFE3 fusion protein binds to the promoter of the NMRK2 gene, leading to its upregulation. Importantly, we established RNA- and protein-based diagnostic methods for identifying Xp11.2 tRCC based on NMRK2 expression levels, and the diagnostic performance of our methods was comparable to a dual-color break-apart fluorescence in situ hybridization assay. Moreover, we successfully identified fresh Xp11.2 tRCC tissues after surgical excision using our diagnostic methods and established an immortalized Xp11.2 tRCC cell line for further research purposes. Functional studies revealed that NMRK2 promotes the progression of Xp11.2 tRCC by upregulating the NAD+/NADH ratio, and supplementation with ß-nicotinamide mononucleotide (NMN) or nicotinamide riboside chloride (NR), effectively rescued the phenotypes induced by the knockdown of NMRK2 in Xp11.2 tRCC. Taken together, these data introduce a new diagnostic indicator capable of accurately distinguishing Xp11.2 tRCC and highlight the possibility of developing novel targeted therapeutics. © 2024 The Pathological Society of Great Britain and Ireland.

Genetic diversity and population structure of Echinococcus multilocularis: An in-silico global analysis.

Objective: Alveolar echinococcosis is caused by Echinococcus multilocularis, a parasite of zoonotic significance with a wide range of intermediate and final hosts, and the parasite survives successfully in diversified conditions. Plentiful studies have been done to study the genetic structure of the population of the parasite and the level of intimate kinship using mitochondrial (mt) DNA. The present study was conducted to investigate the population structure, genetic variation, and phylogenetic relationship of various isolates of E. multiocularis submitted to GenBank worldwide. Sequences of mt genes (mt-cytochrome c oxidase (cox1), mt-NADH dehydrogenase (nad1)) of E. multilocularis were analyzed to achieve the set goals. Materials and Methods: A total of 275 and 124 gene sequences of mt-cox1 and mt-nad1 belonging to E. multilocularis, respectively, were retrieved from the National Center for Biotechnology Information GenBank. The retrieved sequences were subjected to alignment with respective reference sequences using MEGA software. The PopArt software was used to establish median-joining networks, while DnaSp was used to calculate neutrality and diversity indices. MrBayes software was used to investigate the phylogenetic association between haplotypes based on Bayesian phylogeny. Results: Approximately 13 and 20 distinctive haplotypes of nad1 and cox1 genes, respectively, were observed in the present study. In both of the mt genes, diversity indices indicated low haplotype (mt-cox1 = 0.140; mt-nad1 = 0.374) and nucleotide (mt-cox1 = 0.00111; mt-nad1 = 0.00287) diversities. The values of Tajima's D and Fu Fs for a population of both of the genes under study were found to be negative. Conclusion: This study is a maiden attempt to provide insights into the population structure and genetic variation of E. multilocularis on a global scale. However, it is suggested that to better understand the population structure and genetic diversity of E. multilocularis, more geographical locations and amplifications of full-length gene sequences should be considered, which could be helpful in widening the insights into the genetic diversity of E. multilocularis.

Disruption of glucose homeostasis by bacterial infection orchestrates host innate immunity through NAD+/NADH balance.

Metabolic reprogramming is crucial for activating innate immunity in macrophages, and the accumulation of immunometabolites is essential for effective defense against infection. The NAD+/NADH (ratio of nicotinamide adenine dinucleotide and its reduced counterpart) redox couple serves as a critical node that integrates metabolic pathways and signaling events, but how this metabolite couple engages macrophage activation remains unclear. Here, we show that the NAD+/NADH ratio serves as a molecular signal that regulates proinflammatory responses and type I interferon (IFN) responses divergently. Salmonella Typhimurium infection leads to a decreased NAD+/NADH ratio by inducing the accumulation of NADH. Further investigation shows that an increased NAD+/NADH ratio correlates with attenuated proinflammatory responses and enhanced type I IFN responses. Conversely, a decreased NAD+/NADH ratio is linked to intensified proinflammatory responses and restrained type I IFN responses. These results show that the NAD+/NADH ratio is an essential cell-intrinsic factor that orchestrates innate immunity, which enhances our understanding of how metabolites fine-tune innate immunity.

Evaluation of NAD+ precursors for improved metabolism and productivity of antibody-producing CHO cell.

In the previous study, the culture medium was treated with nicotinamide adenine dinucleotide (NAD+) under the hypothesis that NAD+ regeneration is a major factor causing excessive lactate accumulation in Chinese hamster ovary (CHO) cells. The NAD+ treatment improved metabolism by not only reducing the Warburg effect but also enhancing oxidative phosphorylation, leading to enhanced antibody production. Building on this, four NAD+ precursors - nicotinamide mononucleotide (NMN), nicotinic acid (NA), nicotinamide riboside (NR), and nicotinamide (NAM) - were tested to elevate intracellular NAD+ levels more economically. First, the ability of CHO cells to utilize both the salvage and Preiss-Handler pathways for NAD+ biosynthesis was verified, and then the effect of NAD+ precursors on CHO cell cultures was evaluated. These precursors increased intracellular NAD+ levels by up to 70.6% compared to the non-treated group. Culture analysis confirmed that all the precursors induced metabolic changes and that NMN, NA, and NR improved productivity akin to NAD+ treatment, with comparable integral viable cell density. Despite the positive effects such as the increase in the specific productivity and changes in cellular glucose metabolism, none of the precursors surpassed direct NAD+ treatment in antibody titer, presumably due to the reduction in nucleoside availability, as evidenced by the decrease in ATP levels in the NAD+ precursor-treated groups. These results underscore the complexity of cellular metabolism as well as the necessity for further investigation to optimize NAD+ precursor treatment strategies, potentially with the supplementation of nucleoside precursors. Our findings suggest a feasible approach for improving CHO cell culture performances by using NAD+ precursors as medium and feed components for the biopharmaceutical production.

Unlocking mitochondrial dysfunction-associated senescence (MiDAS) with NAD+ - A Boolean model of mitochondrial dynamics and cell cycle control.

The steady accumulation of senescent cells with aging creates tissue environments that aid cancer evolution. Aging cell states are highly heterogeneous. 'Deep senescent' cells rely on healthy mitochondria to fuel a strong proinflammatory secretome, including cytokines, growth and transforming signals. Yet, the physiological triggers of senescence such as reactive oxygen species (ROS) can also trigger mitochondrial dysfunction, and sufficient energy deficit to alter their secretome and cause chronic oxidative stress - a state termed Mitochondrial Dysfunction-Associated Senescence (MiDAS). Here, we offer a mechanistic hypothesis for the molecular processes leading to MiDAS, along with testable predictions. To do this we have built a Boolean regulatory network model that qualitatively captures key aspects of mitochondrial dynamics during cell cycle progression (hyper-fusion at the G1/S boundary, fission in mitosis), apoptosis (fission and dysfunction) and glucose starvation (reversible hyper-fusion), as well as MiDAS in response to SIRT3 knockdown or oxidative stress. Our model reaffirms the protective role of NAD+ and external pyruvate. We offer testable predictions about the growth factor- and glucose-dependence of MiDAS and its reversibility at different stages of reactive oxygen species (ROS)-induced senescence. Our model provides mechanistic insights into the distinct stages of DNA-damage induced senescence, the relationship between senescence and epithelial-to-mesenchymal transition in cancer and offers a foundation for building multiscale models of tissue aging.

Investigation and genetic polymorphism analysis of rodents infected with Echinococcus in Ili Prefecture, Xinjiang Uygur Autonomous Region, China.

Introduction: Alveolar echinococcosis (AE) is a life-threatening disease in humans caused by the larval stage of Echinococcus multilocularis. Domestic animals, dogs, foxes, and small mammals constitute the circular chain of AE. To evaluate the infection, distribution, and genetic polymorphism of AE in the Ili Prefecture (Nilka, Xinyuan and Zhaosu), we conducted this survey. Methods: In June and July 2018, 267 small mammals were captured using water-infusion and mousetrap methods. Combined pathogenic and molecular biological methods were used to observe the histopathology of Echinococcus carried by rodents, amplify the mitochondrial nad1 gene of the pathogen, and investigate the genotype and haplotype diversity of Echinococcus in rodents in Ili Prefecture. Results: Morphological identification revealed that these captured small mammals belonged to three species, with Microtus gregalis being the dominant species (183/267). Pathological and molecular biological results confirmed that E. multilocularis was the pathogen of echinococcosis in small mammals, with an infection rate of 15.73% (42/267). Among the three areas sampled, the highest infection rate of rodents was 25.45% (14/55) in Nilka County. However, there was no significant difference in the infection rates between regions (χ2 = 5.119, p > 0.05). Of the three captured rodent species, M. gregalis had the highest infection rate of 17.49% (32/183), but there was no significant difference in infection rates between the rodent species (χ2 = 1.364, p > 0.05). Phylogenetic analyses showed that the nad1 gene sequences obtained in this study clustered in the same clade as isolates from China. These isolates contained 21 haplotypes (Hap_1-21); Hap_2 was the most common haplotype (9/42). Furthermore, haplotype diversity (0.925 ± 0.027) and nucleotide diversity (0.01139 ± 0.00119) were higher in the Ili Prefecture than in other regions, indicating that population differentiation was high. Tajima's D and Fu's Fs tests were negative (p > 0.10), indicating that the population had expanded. The low fixation index (Fst) ranged from 0.00000 to 0.16945, indicating that the degree of genetic differentiation was different among different populations. Discussion: In summary, Ili Prefecture is a high incidence area of AE, and Microtus spp. may play an important role in the transmission of AE in this area. The results of this study provide basic data for further study of the molecular epidemiology, genetic differences, and control of E. multilocularis in the Ili Prefecture, Xinjiang.

Bridging the gap: RNAylation conjugates RNAs to proteins.

In nature, the majority of known RNA-protein interactions are transient. Our recent study has depicted a novel mechanism known as RNAylation, which covalently links proteins and RNAs. This novel modification bridges the realms of RNA and protein modifications. This review specifically explores RNAylation catalyzed by bacteriophage T4 ADP-ribosyltransferase ModB, with a focus on its protein targets and RNA substrates in the context of Escherichia coli-bacteriophage T4 interaction. Additionally, we discuss the biological significance of RNAylation and present perspectives on RNAylation as a versatile bioconjugation strategy for RNAs and proteins.

The INSIGHT platform: Enhancing NAD(P)-dependent specificity prediction for co-factor specificity engineering.

Enzyme specificity towards cofactors like NAD(P)H is crucial for applications in bioremediation and eco-friendly chemical synthesis. Despite their role in converting pollutants and creating sustainable products, predicting enzyme specificity faces challenges due to sparse data and inadequate models. To bridge this gap, we developed the cutting-edge INSIGHT platform to enhance the prediction of coenzyme specificity in NAD(P)-dependent enzymes. INSIGHT integrates extensive data from principal bioinformatics resources, concentrating on both NADH and NADPH specificities, and utilizes advanced protein language models to refine the predictions. This integration not only strengthens computational predictions but also meets the practical demands of high-throughput screening and optimization. Experimental validation confirms INSIGHT's effectiveness, boosting our ability to engineer enzymes for efficient, sustainable industrial and environmental processes. This work advances the practical use of computational tools in enzyme research, addressing industrial needs and offering scalable solutions for environmental challenges.

Microtubules Sequester Acetylated YAP in the Cytoplasm and Inhibit Heart Regeneration.

BACKGROUND: The Hippo pathway effector YAP (Yes-associated protein) plays an essential role in cardiomyocyte proliferation and heart regeneration. In response to physiological changes, YAP moves in and out of the nucleus. The pathophysiological mechanisms regulating YAP subcellular localization after myocardial infarction remain poorly defined. METHODS: We identified YAP acetylation at site K265 by in vitro acetylation followed by mass spectrometry analysis. We used adeno-associated virus to express YAP-containing mutations that either abolished acetylation (YAP-K265R) or mimicked acetylation (YAP-K265Q) and studied how acetylation regulates YAP subcellular localization in mouse hearts. We generated a cell line with YAP-K265R mutation and investigated the protein-protein interactors by YAP immunoprecipitation followed by mass spectrometry, then validated the YAP interaction in neonatal rat ventricular myocytes. We examined colocalization of YAP and TUBA4A (tubulin α 4A) by superresolution imaging. Furthermore, we developed YAP-K265R and αMHC-MerCreMer (MCM); Yap-loxP/K265R mutant mice to examine the pathophysiological role of YAP acetylation in cardiomyocytes during cardiac regeneration. RESULTS: We found that YAP is acetylated at K265 by CBP (CREB-binding protein)/P300 (E1A-binding protein P300) and is deacetylated by nicotinamide phosphoribosyltransferase/nicotinamide adenine dinucleotide/sirtuins axis in cardiomyocytes. After myocardial infarction, YAP acetylation is increased, which promotes YAP cytoplasmic localization. Compared with controls, mice that were genetically engineered to express a K265R mutation that prevents YAP K256 acetylation showed improved cardiac regenerative ability and increased YAP nuclear localization. Mechanistically, YAP acetylation facilitates its interaction with TUBA4A, a component of the microtubule network that sequesters acetylated YAP in the cytoplasm. After myocardial infarction, the microtubule network increased in cardiomyocytes, resulting in the accumulation of YAP in the cytoplasm. CONCLUSIONS: After myocardial infarction, decreased sirtuin activity enriches YAP acetylation at K265. The growing TUBA4A network sequesters acetylated YAP within the cytoplasm, which is detrimental to cardiac regeneration.

An Open-Label, Pilot Study of Daratumumab SC in Mild to Moderate Alzheimer's Disease.

We conducted a small, open-label, pilot study of daratumumab to explore target engagement, safety, and potential efficacy in patients with mild to moderate Alzheimer's disease. Daratumumab SC 1800 mg was given subcutaneously weekly for 8 weeks, then every 2 weeks for 16 weeks. Flow cytometry to measure the CD38+ proportion of CD8 + CD4- T cells and cognitive assessments were performed at baseline, day 176, and day 246. Daratumumab significantly reduced CD38 + CD8 + CD4- T cells after 24 weeks and this effect persisted 11 weeks thereafter. There was no hematological toxicity or unexpected adverse events. Responder analysis showed no improvement on cognitive outcome measures.

Efficacy of oral nicotinamide mononucleotide supplementation on glucose and lipid metabolism for adults: a systematic review with meta-analysis on randomized controlled trials.

A surge of public interest in NMN supplementation has been observed in recent years. However, whether NMN supplements are effective in improving metabolic health remains unclear. The objective of the review was to assess the effects of NMN supplementation on fasting glucose, triglycerides, total cholesterol, LDL-C, and HDL-C in adults. Studies were located by searching four databases (PubMed, Embase, Cochrane, and Web of Science). Two reviewers independently conducted title/abstract and full-text screening, data extraction, and risk-of-bias assessment. Of the 4049 records reviewed, 12 studies with a total of 513 participants met the criteria for analysis. Random-effects meta-analyses found an overall significant effect of NMN supplementation in elevating blood NAD levels. However, most of the clinically relevant outcomes were not significantly different between NMN supplementation and control group. Risk-of-bias assessment using RoB2 showed some concerns in seven studies and high risk of bias in the other five studies. Together, our findings suggest that an exaggeration of the benefits of NMN supplementation may exist in the field. Although the limited number of eligible studies was sufficiently powered to detect changes in the abovementioned primary outcomes, more studies are needed to conclude about the exact effects of NMN supplementation.

Periplasmic binding proteins Bug69 and Bug27 from Bordetella pertussis are in vitro high-affinity quinolinate binders with a potential role in NAD biosynthesis.

Bordetella's genome contains a large family of periplasmic binding proteins (PBPs) known as Bugs, whose functions are mainly unassigned. Two members, Bug27 and Bug69, have previously been considered potential candidates for the uptake of small pyridine precursors, possibly linked to NAD biosynthesis. Here, we show an in vitro affinity of Bug27 and Bug69 for quinolinate in the submicromolar range, with a marked preference over other NAD precursors. A combined sequence similarity network and genome context analysis identifies a cluster of Bug69/27 homologs that are genomically associated with the NAD transcriptional regulator NadQ and the enzyme quinolinate phosphoribosyltransferase (QaPRT, gene nadC), suggesting a functional linkage to NAD metabolism. Integrating molecular docking and structure-based multiple alignments confirms that quinolinate is the preferred ligand for Bug27 and Bug69.

Development and validation of prognostic signatures of NAD+ metabolism and immune-related genes in colorectal cancer.

Background: Colorectal cancer (CRC) is a prevalent cause of death from malignant tumors. This study aimed to develop a nicotinamide adenine dinucleotide (NAD+) metabolism and immune-related prognostic signature, providing a theoretical foundation for prognosis and therapy in CRC patients. Methods: NAD + metabolism-related and immune-related subtypes of CRC patients were identified by consistent clustering. Differentially expressed genes (DEGs) between the two subtypes of CRC were identified by overlapping. A risk signature was constructed using univariate Cox and least absolute shrinkage and selection operator (LASSO) regression analyses. Independent prognostic predictors were authenticated by Cox analysis. Gene set variation analysis (GSVA) and single-sample gene set enrichment analysis (ssGSEA) were applied to investigate the connection between the prognostic signature and the immune microenvironment. Chemotherapy drug sensitivity and immunotherapy responsiveness were projected using the 'pRRophetic' package and Tumor Immune Dysfunction and Exclusion (TIDE) website. The Human Protein Atlas (HPA) database was used to assess the protein expression of prognostic genes in CRC and normal tissues. Results: Using bioinformatics methods, three prognostic genes related to immune-related NAD + metabolism were identified, and the results were used to establish and verify a prognostic signature related to immune-related NAD + metabolism in CRC patients. Cox regression analysis confirmed that the risk score was a reliable independent prognostic predictor. GSVA and ssGSEA indicated that the prognostic signature was associated with the immune microenvironment. TIDE analysis suggested that the signature might act as an immunotherapy predictor. Chemotherapy sensitivity analysis revealed that COMP was correlated with chemotherapy sensitivity in CRC patients and might be a potential therapeutic target. Conclusion: This study identified NAD + metabolism-immune-related prognostic genes (MOGAT2, COMP, and DNASE1L3) and developed a prognostic signature for CRC prognosis, which is significant for clinical prognosis prediction and treatment strategy decisions for CRC patients.

Metal-free functionalized carbon nitride as a photocatalyst driven by sunlight for acetal synthesis and selective regeneration of NAD(P)H cofactor.

Nicotinamide Adenine Dinucleotide Phosphate (NAD(P)H) plays an important role in numerous biologically significant redox reactions. The photochemical restoration of its oxidized form (NAD(P)+) under physiological conditions is intriguing in the context of integrated photo and catalysis. Herein, we report the functionalized graphitic carbon-based solar light active photocatalyst by doping boron and fluorine in the native graphitic carbon nitride (GCN) (nonfunctionalized) for the regeneration of enzymatically visible light active coenzyme and in photo-acetalization reactions. The metal-free functionalized photocatalyst systems such as BFGCN-x leads to higher yield NADH and NADPH regeneration. They are also capable of catalyzing acetal reactions in the absence of any Lewis and Bronsted acids. The current research endeavor provides the advancement and the application of functionalized GCN-based photocatalysts for NADH (61.89%), NADPH (59.84%) regeneration, and photo-acetalization reactions.

OsLdh7, a rice lactate dehydrogenase, confers stress resilience in rice under cadmium stress through NAD+/NADH regulation.

Lactate dehydrogenase (Ldh, EC 1.1.1.27), an oxidoreductase enzyme catalyses the interconversion of pyruvate to L-lactate and vice-versa with concomitant oxidation and reduction of NADH and NAD+. The enzyme functions as a ROS sensor and mitigates stress response by maintaining NAD+/NADH homeostasis. In this study, we delineated the role of the Ldh enzyme in imparting cadmium stress tolerance in rice. Previously, we identified a putatively active Ldh in rice (OsLdh7) through insilico modelling. Biochemical characterization of the OsLdh7 enzyme revealed it to be optimally active at pH 6.6 in the forward direction and pH 9 in the reverse direction. Overexpression of OsLdh7 in rice cv. IR64, increased tolerance of the transgenic lines to cadmium stress compared to the wild type (WT) at both seedling and reproductive stages. The transgenic lines showed increased enzyme activity in the reverse direction under cadmium stress, attributed to elevated cytosolic pH resulting from increased calcium concentration. This increased NADH content is highly essential for functioning of the ROS scavenging enzymes, RbohD and MPK6. qPCR analysis revealed that the overexpression lines had increased transcript abundance of these genes indicating an effective ROS scavenging mechanism. Additionally, the overexpression lines showed an efficient cadmium sequestration mechanism compared to the WT by increasing the transcript levels of the vacuolar transporters of cadmium as well as total phytochelatin content. Thus, our findings indicated OsLdh7 imparts cadmium stress tolerance in rice through a two-pronged approach by mitigating ROS and sequestering cadmium ions, highlighting its potential for crop improvement programs.

NAD metabolism and heart failure: Mechanisms and therapeutic potentials.

Nicotinamide adenine dinucleotide provides the critical redox pair, NAD+ and NADH, for cellular energy metabolism. In addition, NAD+ is the precursor for de novo NADP+ synthesis as well as the co-substrates for CD38, poly(ADP-ribose) polymerase and sirtuins, thus, playing a central role in the regulation of oxidative stress and cell signaling. Declines of the NAD+ level and altered NAD+/NADH redox states have been observed in cardiometabolic diseases of various etiologies. NAD based therapies have emerged as a promising strategy to treat cardiovascular disease. Strategies that reduce NAD+ consumption or promote NAD+ production have repleted intracellular NAD+ or normalized NAD+/NADH redox in preclinical studies. These interventions have shown cardioprotective effects in multiple models suggesting a great promise of the NAD+ elevating therapy. Mechanisms for the benefit of boosting NAD+ level, however, remain incompletely understood. Moreover, despite the robust pre-clinical studies there are still challenges to translate the therapy to clinic. Here, we review the most up to date literature on mechanisms underlying the NAD+ elevating interventions and discuss the progress of human studies. We also aim to provide a better understanding of how NAD metabolism is changed in failing hearts with a particular emphasis on types of strategies employed and methods to target these pathways. Finally, we conclude with a comprehensive assessment of the challenges in developing NAD-based therapies for heart diseases, and to provide a perspective on the future of the targeting strategies.

Legume-type glutamate dehydrogenase: Structure, activity, and inhibition studies.

Glutamate dehydrogenases (GDHs) are key enzymes at the crossroads of N and C metabolism in plants. Legumes, whose N metabolism is particularly intricate, possess a unique type of GDH. This study presents an analysis of a legume-type GDH (isoform 2) from Medicago truncatula (MtGDH2). We measured MtGDH2 activity in both the Glu â†’ 2-oxoglutarate (2OG) and 2OG â†’ Glu reaction directions and obtained kinetic parameters for Glu, 2OG, NAD+, and NADH. Inhibition assays revealed that compounds possessing di- or tricarboxylates act as inhibitors of plant GDHs. Interestingly, 2,6-pyridinedicarboxylate (PYR) weakly inhibits MtGDH2 compared to Arabidopsis thaliana homologs. Furthermore, we explored tetrazole derivatives to discover 3-(1H-tetrazol-5-yl)benzoic acid (TBA) as an MtGDH2 inhibitor. The kinetic experiments are supported by six crystal structures, solved as: (i) unliganded enzyme, (ii) trapping the reaction intermediate 2-amino-2-hydroxyglutarate and NAD+, and also complexed with NAD+ and inhibitors such as (iii) citrate, (iv) PYR, (v) isophthalate, and (vi) TBA. The complex with TBA revealed a new mode of action that, in contrast to other inhibitors, prevents domain closure. This discovery points to TBA as a starting point for the development of novel GDH inhibitors to study the functions of GDH in plants and potentially boost biomass production.

The evolutionary arch of bioenergetics from prebiotic mechanisms to the emergence of a cellular respiratory chain.

This article proposes an evolutionary trajectory for the development of biological energy producing systems. Six main stages of energy producing system evolution are described, from early evolutionary pyrite-pulled mechanism through the Last Universal Common Ancestor (LUCA) to contemporary systems. We define the Last Pure Chemical Entity (LPCE) as the last completely non-enzymatic entity. LPCE could have had some life-like properties, but lacked genetic information carriers, thus showed greater instability and environmental dependence than LUCA. A double bubble model is proposed for compartmentalization and cellularization as a prerequisite to both highly efficient protein synthesis and transmembrane ion-gradient. The article finds that although LUCA predominantly functioned anaerobically, it was a non-exclusive anaerobe, and sulfur dominated metabolism preceded phosphate dominated one.

Emerging role of sirtuins in non­small cell lung cancer (Review).

Non­small cell lung cancer (NSCLC) is a highly prevalent lung malignancy characterized by insidious onset, rapid progression and advanced stage at the time of diagnosis, making radical surgery impossible. Sirtuin (SIRT) is a histone deacetylase that relies on NAD+ for its function, regulating the aging process through modifications in protein activity and stability. It is intricately linked to various processes, including glycolipid metabolism, inflammation, lifespan regulation, tumor formation and stress response. An increasing number of studies indicate that SIRTs significantly contribute to the progression of NSCLC by regulating pathophysiological processes such as energy metabolism, autophagy and apoptosis in tumor cells through the deacetylation of histones or non­histone proteins. The present review elaborates on the roles of different SIRTs and their mechanisms in NSCLC, while also summarizing novel therapeutic agents based on SIRTs. It aims to present new ideas and a theoretical basis for NSCLC treatment.