Search Results (62)

Aspartate–glutamate carrier 1 (AGC1) deficiency is a rare neurometabolic disorder caused by biallelic pathogenic variants in SLC25A12. Clinically, it is characterized by early-onset developmental and epileptic encephalopathy, often associated with hypomyelination and reduced brain N-acetylaspartate. AGC1 loss reduces malate–aspartate shuttle flux, limiting cytosolic NAD⁺ regeneration and impairing neuronal redox coupling, ATP supply, and aspartate-dependent biosynthesis during brain development. We integrate human genetics with mechanistic evidence from mammalian, Drosophila melanogaster, and Saccharomyces cerevisiae models to describe conserved transport principles and species-specific regulation underlying selective central nervous system vulnerability. We review the management of AGC1 deficiency, focusing on ketogenic therapy. Published reports show reproducible seizure reduction and, in some patients, improved myelination and N-acetylaspartate. However, these responses are heterogeneous and appear to depend on the timing, duration, and stability of ketosis. Preclinical evidence suggests that β-hydroxybutyrate may contribute to metabolic support in AGC1 deficiency. Prospective studies should test disease modification using standardized endpoints plus MRI/¹H-MRS and ketosis measures. Full article

Food-grade microorganisms utilize core cofactors, such as nicotinamide adenine dinucleotide (NAD) and its phosphate form (NADP), to mediate redox reactions and regulate energy metabolism homeostasis as well as biosynthesis of functional components. In metabolic engineering, perturbation of the NAD(P)⁺/NAD(P)H network may significantly disrupt intracellular redox homeostasis, leading to impaired strain growth and limited synthesis of targeted functional products. This review systematically examines the latest research progress in the field of food-grade microbial cofactor engineering, focusing on the key mechanisms and synergistic pathways of core strategies, such as metabolic flux optimization and cofactor regeneration systems, in maintaining cellular redox homeostasis and enhancing the biosynthesis of functional ingredients. Future research should focus on exploring the potential for integrating multi-omics approaches and intelligent control technologies, proposing innovative approaches to address the challenges of industrialized production, and providing theoretical support for food biomanufacturing. Full article

Lactate dehydrogenase (LDH) is a key glycolytic enzyme that catalyzes the interconversion of pyruvate and lactate, with LDHA gaining particular attention for its overexpression in various malignancies and pivotal role in the Warburg effect-driven metabolic reprogramming. Elevated LDHA activity supports rapid ATP production under hypoxic conditions, maintains NAD⁺ regeneration, and promotes lactate accumulation, creating an acidic tumor microenvironment (TME) that favors invasion and immune evasion. Accumulating evidence demonstrates that LDHA is essential for primary tumor growth and critically involved in circulating tumor cell (CTC) survival, anoikis resistance, and metastatic spread. These functions are mediated by its regulation of adhesion molecules, cytoskeletal remodeling, and energy adaptation that enable CTCs to withstand mechanical shear stress and immune surveillance in the bloodstream. Pharmacological inhibition of LDHA, particularly via sodium oxamate (oxamate), has shown substantial potential in reducing metastasis and enhancing chemotherapy sensitivity in preclinical models. Oxamate has emerged as a promising candidate for metabolic cancer therapy due to its unique double effects on tumor metabolism and anti-tumor immunity, which are an advantage rarely highlighted in broader LDHA-focused reviews. This review synthesizes the molecular mechanisms through which LDHA drives tumor progression, dissects its context-specific functions in CTC biology, and evaluates the translational potential of LDHA-targeted strategies, with a focused emphasis on oxamate, as a transformative anti-metastatic therapeutic paradigm. By filling a critical gap in synthesizing oxamate’s distinct metabolic–immune regulatory actions, this work addresses an unmet need in the management of advanced, treatment-refractory cancers. Full article

Metabolic dysfunction-associated steatotic liver disease (MASLD) is becoming increasingly prevalent worldwide, particularly among individuals with obesity and type 2 diabetes (T2D). MASLD remains potentially reversible in the early phases but, without timely intervention, it can progress to metabolic dysfunction-associated steatohepatitis (MASH) and hepatic fibrosis, which in turn may advance to cirrhosis and hepatocellular carcinoma over time. With no pharmacological treatments specifically indicated for MASLD, current therapeutic strategies include lifestyle modifications, including dietary modifications. Niacin and its molecular derivatives (collectively belonging to the vitamin B3 group) play a central role in metabolic processes, especially through their involvement in the biosynthesis of the oxidized form of nicotinamide adenine dinucleotide (NAD⁺). A growing body of preclinical evidence suggests that reduced NAD⁺ levels are a hallmark of MASLD, and that NAD⁺ precursors may help attenuate disease progression through multiple mechanisms, including sirtuin 1 (SIRT1)-mediated inhibition of hepatic lipogenesis. Although these findings from experimental models suggest a potential role for niacin and related molecular derivatives as a modulators of MASLD-related pathways, evidence from human studies remains limited and inconsistent. For instance, interventional studies evaluating niacin or molecular derivatives supplementation have reported variable findings, with several trials showing limited meaningful benefits on MASLD-related outcomes. Consequently, further well-designed, controlled trials are needed to clarify therapeutic efficacy, dose–response relationship, and the feasibility of integrating niacin derivatives into dietary or therapeutic strategies aimed at reducing liver fat and improving adverse metabolic outcomes. This review aims to (i) summarize mechanistic insights on the role of niacin as a source of NAD⁺ on experimental MASLD and (ii) critically evaluate the available human evidence on the effect of supplemental niacin and derivatives in the prevention of MASLD development and its progression to MASH and fibrosis. Full article

Hydrogenases are key enzymes in microbial energy metabolism, catalyzing the reversible conversion between molecular hydrogen and protons. Among them, [NiFe]-hydrogenases are particularly attractive for biocatalytic applications due to the oxygen tolerance of several members of this class and their ability to couple hydrogen oxidation with redox cofactor regeneration. In this study, a recombinant soluble [NiFe]-hydrogenase from Cupriavidus necator H16 was successfully expressed in Escherichia coli BL21 (DE3), purified, and characterised with a focus on its applicability for NAD⁺ regeneration. Unlike previous studies that primarily used native C. necator extracts or complex maturation systems, this work provides the first quantitative demonstration that an aerobically purified recombinant soluble [NiFe]-hydrogenase expressed in E. coli can function effectively as an NAD⁺ regeneration catalyst and operate within multi-enzymatic cascade reactions under application-relevant conditions. The crude recombinant enzyme displayed a volumetric activity of 0.273 ± 0.024 U/mL and a specific activity of 0.018 ± 0.002 U/mg_cells in the hydrogen oxidation assay, while purification yielded a specific activity of 0.114 ± 0.001 U/mg with an overall recovery of 79.2%. The enzyme exhibited an optimal temperature of 35 °C and a pH optimum of 7.00. Thermal stability analysis revealed rapid deactivation at 40 °C (k_d = 0.4186 ± 0.0788 h⁻¹, t_1/2 ≈ 1.7 h) and substantially slower deactivation at 4 °C (k_d = 0.1141 ± 0.0139 h⁻¹, t_1/2 ≈ 6.1 h). Batch NADH oxidation experiments confirmed efficient cofactor turnover and high specificity towards NADH over NADPH. Finally, integration of the hydrogenase into a one-pot two-enzyme glucose oxidation system demonstrated its capacity for in situ NAD⁺ regeneration, although the reaction stopped after approximately 5 min due to acidification from gluconic acid formation, highlighting pH control as a key requirement for future process optimization. Full article

Biocatalysis is fundamental to biological processes and sustainable chemical productions. Over time, the biocatalysis strategy has been widely researched. Initially, biomanufacturing and catalysis of high-value chemicals were carried out through direct immobilization and application of biocatalysts, including natural enzymes and living cells. With the evolution of green chemistry and environmental concern, hybrid photoelectro-biocatalysis (HPEB) platforms are seen as a new approach to enhance biocatalysis. This strategy greatly expands the domain of natural biocatalysis, especially for bio-based components. The selective valorization of renewable furan derivatives, such as 5-hydroxymethylfurfural (HMF) and furfural, is central to advancing biomass-based chemical production. Biocatalysis offers high chemo-, regio-, and stereo-selectivity under mild conditions compared with traditional chemical catalysis, yet it is often constrained by the costly and inefficient regeneration of redox cofactors like NAD(P)H. Photoelectrocatalysis provides a sustainable means to supply reducing equivalents using solar or electrical energy. In recent years, hybrid systems that integrate biocatalysis with photoelectrocatalysis have emerged as a promising strategy to overcome this limitation. This review focuses on recent advances in such systems, where photoelectrochemical platforms enable in situ cofactor regeneration to drive enzymatic transformations of furan-based substrates. We critically analyze representative coupling strategies, materials and device configurations, and reaction engineering approaches. Finally, we outline future directions for developing efficient, robust, and industrially viable hybrid catalytic platforms for green biomass valorization. Full article

Sarcopenia, the progressive loss of muscle mass, strength, and regenerative capacity with age, is driven by interconnected processes such as oxidative stress, chronic inflammation, mitochondrial dysfunction, and reduced activity of muscle stem cells. As the population ages, nutritional strategies that target these mechanisms are becoming increasingly important. This review focuses on nicotinamide (vitamin B3) and pyridoxine (vitamin B6), two essential micronutrients found in functional foods, which play complementary roles in redox regulation, immune balance, and muscle repair. Nicotinamide supports nicotinamide adenine dinucleotide (NAD⁺) metabolism, boosts mitochondrial function, and activates sirtuin pathways involved in autophagy and stem cell maintenance. Pyridoxine, via its active form pyridoxal 5′-phosphate (PLP), is key to amino acid metabolism, antioxidant defense, and the regulation of inflammatory cytokines. We summarize how these vitamins influence major molecular pathways such as Sirtuin1 (SIRT1), protein kinase B (AKT)/mechanistic target of rapamycin (mTOR), Nuclear factor-κB (NF-κB), and Nrf2, contributing to improved myogenic differentiation and protection of the aging muscle environment. We also highlight emerging preclinical and clinical data, including studies suggesting possible synergy between B3 and B6. Finally, we discuss how biomarkers such as PLP, nicotinamide mononucleotide (NMN), and C-reactive protein (CRP) may support the development of personalized nutrition strategies using these vitamins. Safe, accessible, and mechanistically grounded, nicotinamide and pyridoxine offer promising tools for sarcopenia prevention and healthy aging. Full article

Accurate diagnosis of diseases in patients is crucial, particularly in older individuals, where the focus is often placed primarily on advanced age and its associated symptoms. However, advancements in technology and research have revealed that certain diseases traditionally linked to aging can also manifest in younger populations, demonstrating similar bodily changes. One such condition is sarcopenia, a degenerative disease of skeletal muscle that arises from various pathological processes affecting the tissues. In this study, we developed a liposomal formulation based on 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), in which both nicotinamide mononucleotide (NMN) and Matrigel (Mgel) were co-encapsulated, each playing a distinct role in the management of sarcopenia. NMN is known to stimulate the increase of NAD+ levels, while Matrigel enhances the activity of satellite cells, thereby facilitating muscle fiber regeneration and stabilizing protein levels. Results from the DLS, SEM, and TEM analyses revealed significant differences attributed to the type of therapeutic agent used and the synthesis parameters. Additionally, the drug release profile underscored the complementary nature and significance of selecting the appropriate active substances for effective treatment strategies. The in vitro investigations aimed to assess the potential of DMPC lipid vesicles loaded with NMN, either alone or in combination with Matrigel, to counteract sarcopenia-associated oxidative stress and mitochondrial dysfunction. The results showed that both NMN-based formulations reduced oxidative damage, preserved mitochondrial function, and maintained cytoskeletal integrity in a hydrogen peroxide-induced model of sarcopenia. Importantly, the formulation containing both NMN and Matrigel demonstrated superior protective effects, suggesting a synergistic role of the extracellular matrix components in enhancing muscle cell resilience. These findings support the use of DMPC-based delivery systems as promising candidates for sarcopenia therapy and warrant further investigation into their mechanisms of action in preventing muscle cell degeneration. Full article

The aim of this work is to study the metabolism of Actinobacillus succinogenes in greater detail with the aim of optimizing succinate production and creating a metabolic model. The inhibitory properties of various substances were first investigated. It was found that the nature and availability of the gas can have a strong influence on metabolism. By studying the effects of different gas sources, it was found that when A. succinogenes lacks a CO₂ source, the metabolism completely switches to the C3 pathway. This also completely changes the path within the pathway. In the presence of CO₂, significantly more formate (2.44 ± 0.04 g L⁻¹) and significantly less acetate (1.63 ± 0.03 g L⁻¹) was produced. In contrast, in the absence of CO₂, the formate concentration was 1.94 ± 0.12 g L⁻¹, and the acetate concentration was 2.73 ± 0.15 g L⁻¹. In addition, larger amounts of ethanol (1.34 ± 0.28 g L⁻¹) were produced in the absence of CO₂, whereas hardly any ethanol was produced otherwise. All these results show that, in the absence of a CO₂ source, the organism has to regenerate much more NADH to NAD⁺ via the C3 pathway. In the subsequent investigation of the CO₂ source, an increase in product concentration from 1.55 ± 0.13 g L⁻¹ to 6.11 ± 0.09 g L⁻¹ was achieved by combining gaseous CO₂ with NaHCO₃. It was shown that a microaerobic environment is not sufficient to influence the metabolism of the organism towards lactate formation. Using the model, it was possible to verify the main metabolic pathways observed during experimental bioreactor runs on a 2-L scale. By conducting further modification, it is now possible to use the model to predict the effects of an external electron supply on the redox metabolism. Full article

Background/Objectives: Exercise training (ET) can improve wound healing and prevent the recurrence of skin lesions. Aerobic ET stimulates the NAD+-dependent deacetylase sirtuin 1 (SIRT1). The beneficial effects of ET and SIRT1 activation in wound healing have been characterized when considered separately. This study aimed to investigate the potential role of SIRT1 as a mediator of the effects of sera isolated from athletes who regularly participate in aerobic ET (middle-distance running, MDR) on cells primarily involved in wound healing. Methods: Human keratinocytes, fibroblasts and endothelial cells were conditioned with sera from middle-distance runners and age-matched sedentary subjects (sed). Cell motility, angiogenesis and the expression of key biomarkers of cell activation were evaluated in the presence or absence of the selective SIRT1 inhibitor EX-527. Results: Higher SIRT1 activity was detected in all of the cell lines conditioned with the MDR group sera compared with that in the cells in the sed group sera. The involvement of SIRT1 was demonstrated by EX-527’s selective inhibition. Alongside the increase in SIRT1 activity, a marked increase in migration, invasion and angiogenesis was observed. The levels of E-cadherin decreased while those of integrin β1 and vinculin increased in the keratinocytes and fibroblasts conditioned with the MDR group sera compared to these values with the sed group sera, respectively. Increased levels of differentiation markers, such as involucrin in the keratinocytes, FAP1α in the fibroblasts and CD31 in the endothelial cells, were observed with the MDR group sera compared to these values using the sed group sera. Conclusions: The ex vivo/in vitro approach used here links aerobic ET-induced SIRT1 activity to proper tissue regeneration. Full article

Bacterial and eukaryotic dihydrofolate reductase (DHFR) enzymes are essential for DNA synthesis and are differentially sensitive to the competitive inhibitors trimethoprim and methotrexate. Unexpectedly, trimethoprim did not reduce Wolbachia abundance, and the wStri DHFR homolog contained amino acid substitutions associated with trimethoprim resistance in E. coli. A phylogenetic tree showed good association of DHFR protein sequences with supergroup A and B assignments. In contrast, DHFR is not encoded by wFol (supergroup E) and wBm (supergroup D) or by genomes of the closely related genera Anaplasma, Ehrlichia, Neorickettsia, and possibly Orientia. In E. coli and humans, DHFR participates in a coupled reactions with the conventional thymidylate synthase (TS) encoded by thyA to produce the dTMP required for DNA synthesis. In contrast, Wolbachia and other Rickettsiales express the unconventional FAD-TS enzyme encoded by thyX, even when folA is present. The exclusive use of FAD-TS suggests that Wolbachia DHFR provides a supplementary rather than an essential function for de novo synthesis of dTMP, possibly reflecting the relative availability of, and competing demands for, FAD and NAD coenzymes in the diverse intracellular environments of its hosts. Whether encoded by thyA or thyX, TS produces dTMP by transferring a methyl group from methylene tetrahydrofolate to dUMP. In the Rickettsiales, serine hydroxymethyltransferase (SMHT), encoded by a conserved glyA gene, regenerates methylene tetrahydrofolate. Unlike thyA, thyX lacks a human counterpart and thus provides a potential target for the treatment of infections caused by pathogenic members of the Rickettsiales. Full article

Osteogenesis imperfecta (OI) is a hereditary disorder characterized by bones that are fragile and prone to breaking. The efficacy of existing therapies for OI is limited, and they are associated with potentially harmful side effects. OI is primarily due to a mutation of collagen type I and hence impairs bone regeneration. Mesenchymal stem cell (MSC) therapy is an attractive strategy to take advantage of the potential benefits of these multipotent stem cells to address the underlying molecular defects of OI by differentiating osteoblasts, paracrine effects, or immunomodulation. The maintenance of mitochondrial homeostasis is an essential component for improving the curative efficacy of MSCs in OI by affecting the differentiation, signaling, and immunomodulatory functions of MSCs. In this review, we highlight the MSC-based therapy pathway in OI and introduce the MSC regulation mechanism by mitochondrial homeostasis. Strategies aiming to modulate the metabolism and reduce the oxidative stress, as well as innovative strategies based on the use of compounds (resveratrol, NAD+, α-KG), antioxidants, and nanomaterials, are analyzed. These findings may enable the development of new strategies for the treatment of OI, ultimately resulting in improved patient outcomes. Full article

The growing demand for sustainable chemical production has spurred significant interest in biocatalysis. This study is framed within the biocatalytic production of 1,3-dihydroxyacetone (DHA) from glycerol, a byproduct of biodiesel manufacturing. The main goal of this study is to address the challenge of identifying the optimal operating conditions. To achieve this, catalytic potential, a lumped parameter that considers both the activity and stability of immobilized biocatalysts, was used to guide the design of a multi-enzymatic system. The multi-enzymatic system comprises glycerol dehydrogenase (GlyDH) and NADH oxidase (NOX). The enzymatic oxidation of glycerol to DHA catalyzed by GlyDH requires the cofactor NAD+. The integration of NOX into a one-pot reactor allows for the in situ regeneration of NAD+, enhancing the overall efficiency of the process. Furthermore, immobilization on Ni⁺² agarose chelated supports, combined with post-immobilization modifications (glutaraldehyde crosslinking for GlyDH), significantly improved the stability and activity of both enzymes. The catalytic potential enabled the identification of the optimal operating conditions, which were 30 °C and pH 7.5, favoring NOX stability. This work establishes a framework for the rational design and optimization of multi-enzymatic systems. It highlights the crucial interplay between individual enzyme properties and process conditions to achieve efficient and sustainable biocatalytic transformations. Full article

Background: Sterile α and Toll/IL-1 receptor motif-containing 1 (SARM1) is a central regulator of programmed axon death and a crucial nicotinamide adenine dinucleotide (NAD+) hydrolase (NADase) in mammalian tissues, hydrolyzing NAD+ and playing an important role in cellular NAD+ recycling. Abnormal SARM1 expression is linked to axon degeneration, which causes disability and disease progression in many neurodegenerative disorders of the peripheral and central nervous systems. Methods: In this study, we use PC6 assay of hydrolase activity, DRG axon regeneration and CIPN model to screen for potent SARM1 Inhibitors. Results: Two novel SARM1 inhibitors (compound 174 and 331P1) are charcterized for its high potency for SARM1 NADase. In a chemotherapy-induced peripheral neuropathy (CIPN) myopathy model, compound 331P1 treatment prevented the decline in neurofilament light chain (NfL) levels caused by axonal injury in a dose-dependent manner, associated with elevated intraepidermal nerve fiber (IENF) intensity in mouse foot paw tissue, suggesting its functionality in reversing axon degeneration. Conclusions: The newly designed SARM1 inhibitor 331P1 is a promising candidate due to its excellent in vivo efficacy, favorable CYP inhibition properties, and attractive safety profiles. The 331P1 compound possesses the potential to be developed as a novel neuroprotective therapy that can prevent or halt the neurodegenerative process in CIPN. Full article

Cancer cells metabolize a large fraction of glucose to lactate, even under a sufficient oxygen supply. This phenomenon—the “Warburg Effect”—is often regarded as not yet understood. Cancer cells change gene expression to increase the uptake and utilization of glucose for biosynthesis pathways and glycolysis, but they do not adequately up-regulate the tricarboxylic acid (TCA) cycle and oxidative phosphorylation (OXPHOS). Thereby, an increased glycolytic flux causes an increased production of cytosolic NADH. However, since the corresponding gene expression changes are not neatly fine-tuned in the cancer cells, cytosolic NAD⁺ must often be regenerated by loading excess electrons onto pyruvate and secreting the resulting lactate, even under sufficient oxygen supply. Interestingly, the Michaelis constants (K_M values) of the enzymes at the pyruvate junction are sufficient to explain the priorities for pyruvate utilization in cancer cells: 1. mitochondrial OXPHOS for efficient ATP production, 2. electrons that exceed OXPHOS capacity need to be disposed of and secreted as lactate, and 3. biosynthesis reactions for cancer cell growth. In other words, a number of cytosolic electrons need to take the “emergency exit” from the cell by lactate secretion to maintain the cytosolic redox balance. Full article