Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Nicotinamide adenine dinucleotide (NAD⁺) is a central and pleiotropic metabolite involved in multiple cellular energy metabolism, such as cell signaling, DNA repair, protein modifications, and so on. Evidence suggests that NAD⁺ levels decline with age, obesity, and hypertension, which are all significant CVD risk factors. In addition, the therapeutic elevation of NAD⁺ levels reduces chronic low-grade inflammation, reactivates autophagy and mitochondrial biogenesis, and enhances antioxidation and metabolism in vascular cells of humans with vascular disorders. In preclinical animal models, NAD⁺ boosting also extends the health span, prevents metabolic syndrome, and decreases blood pressure. Moreover, NAD⁺ storage by genetic, pharmacological, or natural dietary NAD⁺-increasing strategies has recently been shown to be effective in improving the pathophysiology of cardiac and vascular health in different animal models and humans. Here, we discuss NAD⁺-related mechanisms pivotal for vascular health and summarize recent research on NAD⁺ and its association with vascular health and disease, including hypertension, atherosclerosis, and coronary artery disease. This review also assesses various NAD⁺ precursors for their clinical efficacy and the efficiency of NAD⁺ elevation in the prevention or treatment of major CVDs, potentially guiding new therapeutic strategies.
Humans ; Cardiovascular Diseases/physiopathology* ; NAD/metabolism* ; Animals ; Hypertension/metabolism*

OBJECTIVE: To explore the mechanism by which ω-3 polyunsaturated fatty acids (hereinafter referred to as "ω-3") exert antioxidant stress protection and promote osteogenic differentiation in MC3T3-E1 cells, and to reveal the relationship between ω-3 and the key antioxidant stress pathway involving nuclear factor E2-related factor 2 (Nrf2) and NAD (P) H quinone oxidoreductase 1 (NQO1) in MC3T3-E1 cells. METHODS: The optimal concentration of H ₂O ₂ (used to establish the oxidative stress model of MC3T3-E1 cells in vitro) and the optimal intervention concentrations of ω-3 were screened by cell counting kit 8. MC3T3-E1 cells were divided into blank control group, oxidative stress group (H ₂O ₂), low-dose ω-3 group (H ₂O ₂+low-dose ω-3), and high-dose ω-3 group (H ₂O ₂+high-dose ω-3). After osteoblastic differentiation for 7 or 14 days, the intracellular reactive oxygen species (ROS) level was measured by fluorescence staining and flow cytometry, and the mitochondrial morphological changes were observed by biological transmission electron microscope; the expression levels of Nrf2, NQO1, heme oxygenase 1 (HO-1), Mitofusin 1 (Mfn1), and Mfn2 were detected by Western blot to evaluate the cells' antioxidant stress capacity; the expression levels of Runt-related transcription factor 2 (RUNX2) and osteocalcin (OCN) were detected by immunofluorescence staining and Western blot; osteogenic potential of MC3T3-E1 cells was evaluated by alkaline phosphatase (ALP) staining and alizarin red staining. RESULTS: Compared with the oxidative stress group, the content of ROS in the low and high dose ω-3 groups significantly decreased, and the protein expressions of Nrf2, NQO1, and HO-1 significantly increased ( P<0.05). At the same time, the mitochondrial morphology of MC3T3-E1 cells improved, and the expressions of mitochondrial morphology-related proteins Mfn1 and Mfn2 significantly increased ( P<0.05). ALP staining and alizarin red staining showed that the low-dose and high-dose ω-3 groups showed stronger osteogenic ability, and the expressions of osteogenesis-related proteins RUNX2 and OCN significantly increased ( P<0.05). And the above results showed a dose-dependence in the two ω-3 treatment groups ( P<0.05). CONCLUSION ω-3 can enhance the antioxidant capacity of MC3T3-E1 cells under oxidative stress conditions and upregulate their osteogenic activity, possibly through the Nrf2/NQO1 signaling pathway.
Oxidative Stress/drug effects* ; NF-E2-Related Factor 2/metabolism* ; NAD(P)H Dehydrogenase (Quinone)/metabolism* ; Animals ; Mice ; Osteogenesis/drug effects* ; Cell Differentiation/drug effects* ; Fatty Acids, Omega-3/pharmacology* ; Signal Transduction/drug effects* ; Osteoblasts/drug effects* ; Reactive Oxygen Species/metabolism* ; Cell Line ; Hydrogen Peroxide/pharmacology* ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Antioxidants/pharmacology* ; Heme Oxygenase-1/metabolism*

NAD(P)H: quinone oxidoreductase 1 (NQO1) is a flavin protease highly expressed in various cancer cells. NQO1 catalyzes a futile redox cycle in substrates, leading to substantial reactive oxygen species (ROS) production. This ROS generation results in extensive DNA damage and elevated poly (ADP-ribose) polymerase 1 (PARP1)-mediated consumption of nicotinamide adenine dinucleotide (NAD⁺), ultimately causing cell death. Nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the NAD⁺ salvage synthesis pathway, emerges as a critical target in cancer therapy. The concurrent inhibition of NQO1 and NAMPT triggers hyperactivation of PARP1 and intensive NAD⁺ depletion. In this study, we designed, synthesized, and assessed a novel series of proqodine A derivatives targeting both NQO1 and NAMPT. Among these, compound T8 demonstrated potent antitumor properties. Specifically, T8 selectively inhibited the proliferation of MCF-7 cells and induced apoptosis through mechanisms dependent on both NQO1 and NAMPT. This discovery offers a promising new molecular entity for advancing anticancer research.
Humans ; NAD/metabolism* ; Cell Line, Tumor ; Reactive Oxygen Species/metabolism* ; Nicotinamide Phosphoribosyltransferase/metabolism* ; Cytokines/metabolism* ; Quinones ; Oxidoreductases

Nicotinamide adenine dinucleotide（NADH） in its reduced form of is a key coenzyme in redox reactions, essential for maintaining energy homeostasis.NADH and its oxidized counterpart, NAD+, form a redox couple that regulates various biological processes, including calcium homeostasis, synaptic plasticity, anti-apoptosis, and gene expression. The reduction of NAD+/NADH levels is closely linked to mitochondrial dysfunction, which plays a pivotal role in the cascade of various neurodegenerative disorders, including Parkinson's disease and Alzheimer's disease.Auditory neuropathy（AN） is recognized as a clinical biomarker in neurodegenerative disorders. Furthermore, mitochondrial dysfunction has been identified in patients with mutations in genes like OPA1and AIFM1. However, effective treatments for these conditions are still lacking. Increasing evidence suggests that administratering NAD+ or its precursors endogenously may potentially prevent and slow disease progression by enhancing DNA repair and improving mitochondrial function. Therefore, this review concentrates on the metabolic pathways of NAD+/NADH production and their biological functions, and delves into the therapeutic potential and mechanisms of NADH in treating AN.
Humans ; NAD/metabolism* ; Neurodegenerative Diseases/metabolism* ; Mitochondria ; Oxidation-Reduction ; Mitochondrial Diseases

β-Nicotinamide mononucleotide (NMN), as the precursor of nicotinamide adenine dinucleotide (NAD), plays an important role in enhancing NAD levels. Intake of NMN can alter the composition and vitality of gut microbiota, restore mitochondrial function, inhibit inflammatory pathways, improve metabolism, counteract oxidative stress, and alleviate inflammation. NMN significantly improves recovery from aging-related diseases, such as diminished heart function, reduced fertility, memory decline, and diabetes. NMN demonstrates both efficacy and safety in anti-aging. The use of NMN in China has gradually gained acceptance, highlighting the importance of exploring the mechanism of NMN in anti-aging effects and improving the biosynthesis of NMN. In addition, NMN in combination with stem cells hold promise in the treatment of aging-related degenerative diseases and promote overall human and animal health.
Humans ; Nicotinamide Mononucleotide/pharmacology* ; Aging/physiology* ; Animals ; Oxidative Stress/drug effects* ; Gastrointestinal Microbiome ; NAD/metabolism*

Auditory neuropathy spectrum disorder (ANSD) represents a variety of sensorineural deafness conditions characterized by abnormal inner hair cells and/or auditory nerve function, but with the preservation of outer hair cell function. ANSD represents up to 15% of individuals with hearing impairments. Through mutation screening, bioinformatic analysis and expression studies, we have previously identified several apoptosis-inducing factor (AIF) mitochondria-associated 1 (AIFM1) variants in ANSD families and in some other sporadic cases. Here, to elucidate the pathogenic mechanisms underlying each AIFM1 variant, we generated AIF-null cells using the clustered regularly interspersed short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system and constructed AIF-wild type (WT) and AIF-mutant (mut) (p.‍T260A, p.‍R422W, and p.‍R451Q) stable transfection cell lines. We then analyzed AIF structure, coenzyme-binding affinity, apoptosis, and other aspects. Results revealed that these variants resulted in impaired dimerization, compromising AIF function. The reduction reaction of AIF variants had proceeded slower than that of AIF-WT. The average levels of AIF dimerization in AIF variant cells were only 34.5%‍‒‍49.7% of that of AIF-WT cells, resulting in caspase-independent apoptosis. The average percentage of apoptotic cells in the variants was 12.3%‍‒‍17.9%, which was significantly higher than that (6.9%‍‒‍7.4%) in controls. However, nicotinamide adenine dinucleotide (NADH) treatment promoted the reduction of apoptosis by rescuing AIF dimerization in AIF variant cells. Our findings show that the impairment of AIF dimerization by AIFM1 variants causes apoptosis contributing to ANSD, and introduce NADH as a potential drug for ANSD treatment. Our results help elucidate the mechanisms of ANSD and may lead to the provision of novel therapies.
Humans ; Apoptosis Inducing Factor/metabolism* ; NAD/metabolism* ; Dimerization ; Apoptosis

Nicotinamide mononucleotide (NMN) is one of the key precursors of coenzyme Ⅰ (NAD⁺). NMN exists widely in a variety of organisms, and β isomer is its active form. Studies have shown that β-NMN plays a key role in a variety of physiological and metabolic processes. As a potential active substance in anti-aging and improving degenerative and metabolic diseases, the application value of β-NMN has been deeply explored, and it is imminent to achieve large-scale production. Biosynthesis has become the preferred method to synthesize β-NMN because of its high stereoselectivity, mild reaction conditions, and fewer by-products. This paper reviews the physiological activity, chemical synthesis as well as biosynthesis of β-NMN, highlighting the metabolic pathways involved in biosynthesis. This review aims to explore the potential of improving the production strategy of β-NMN by using synthetic biology and provide a theoretical basis for the research of metabolic pathways as well as efficient production of β-NMN.
Nicotinamide Mononucleotide/metabolism* ; NAD/metabolism*

Citric Acid Cycle ; NAD/metabolism* ; Photons ; Neurons/metabolism*

The redox biosynthesis system has important applications in green biomanufacturing of chiral compounds. Formate dehydrogenase (FDH) catalyzes the oxidation of formate into carbon dioxide, which is associated with the reduction of NAD(P)⁺ into NAD(P)H. Due to this property, FDH is used as a crucial enzyme in the redox biosynthesis system for cofactor regeneration. Nevertheless, the application of natural FDH in industrial production is hampered by low catalytic efficiency, poor stability, and inefficient coenzyme utilization. This review summarized the structural characteristics and catalytic mechanism of FDH, as well as the advances in protein engineering of FDHs toward improved enzyme activity, catalytic efficiency, stability and coenzyme preference. The applications of using FDH as a coenzyme regeneration system for green biomanufacturing of chiral compounds were summarized.
Catalysis ; Coenzymes/metabolism* ; Formate Dehydrogenases/metabolism* ; NAD/metabolism* ; Protein Engineering

OBJECTIVES: Myocardial ischemia reperfusion injury (IRI) occurs occasionally in the process of ischemic heart disease. Sevoflurane preconditioning has an effect on attenuating IRI. Preserving the structural and functional integrity of mitochondria is the key to reduce myocardial IRI. Silent information regulator 3 (SIRT3), a class of nicotinamide adenine dinucleotide (NAD⁺) dependent deacetylases, is an important signal-regulating molecule in mitochondria. This study aims to explore the role of mitochondrial NAD⁺-SIRT3 pathway in attenuating myocardial IRI in rats by sevoflurane preconditioning. METHODS: A total of 60 male Sprague Dawley (SD) rats were randomly divided into 5 groups (n=12): A sham group (Sham group), an ischemia reperfusion group (IR group), a sevoflurane preconditioning group (Sev group, inhaled 2.5% sevoflurane for 30 min), a sevoflurane preconditioning+SIRT3 inhibitor 3-TYP group (Sev+3-TYP group, inhaled 2.5% sevoflurane for 30 min and received 5 mg/kg 3-TYP), and a 3-TYP group (5 mg/kg 3-TYP). Except for the Sham group, the IR model in the other 4 groups was established by ligating the left anterior descending coronary artery. The size of myocardial infarction was determined by double staining. Serum cardiac troponin I (cTnI) level was measured. The contents of NAD⁺ and ATP, the activities of mitochondrial complexes I, II, and IV, the content of MDA, the activity of SOD, and the changes of mitochondrial permeability were measured. The protein expression levels of SIRT3, SOD2, catalase (CAT), and voltage dependent anion channel 1 (VDAC1) were detected by Western blotting. The ultrastructure of myocardium was observed under transmission electron microscope. MAP and HR were recorded immediately before ischemia (T0), 30 min after ischemia (T1), 30 min after reperfusion (T2), 60 min after reperfusion (T3), and 120 min after reperfusion (T4). RESULTS: After ischemia reperfusion, the content of NAD⁺ in cardiac tissues and the expression level of SIRT3 protein were decreased (both P<0.01), and an obvious myocardial injury occurred, including the increase of myocardial infarction size and serum cTnI level (both P<0.01). Correspondingly, the mitochondria also showed obvious damage on energy metabolism, antioxidant function, and structural integrity, which was manifested as: the activities of mitochondrial complexes I, II, and IV, ATP content, protein expression levels of SOD2 and CAT were decreased, while MDA content, VDAC1 protein expression level and mitochondrial permeability were increased (all P<0.01). Compared with the IR group, the content of NAD⁺ in cardiac tissues and the expression level of SIRT3 protein were increased in the Sev group (both P<0.01); the size of myocardial infarction and the level of serum cTnI were decreased in the Sev group (both P<0.01); the activities of mitochondrial complexes I, II, and IV, ATP content, protein expression levels of SOD2 and CAT were increased, while MDA content, VDAC1 protein expression level, and mitochondrial permeability were decreased in the Sev group (all P<0.01). Compared with the Sev group, the content of NAD⁺ in cardiac tissues and the expression level of SIRT3 protein were decreased in the Sev+3-TYP group (both P<0.01); the size of myocardial infarction and the level of serum cTnI were increased in the Sev+3-TYP group (both P<0.01); the activities of mitochondrial complexes I, II, and IV, ATP content, protein expression levels of SOD2 and CAT were decreased, while MDA content, VDAC1 protein expression level, and mitochondrial permeability were increased in the Sev+3-TYP group (all P<0.01). CONCLUSIONS Sevoflurane preconditioning attenuates myocardial IRI through activating the mitochondrial NAD⁺-SIRT3 pathway to preserve the mitochondrial function.
Adenosine Triphosphate/metabolism* ; Animals ; Male ; Mitochondria/metabolism* ; Myocardial Infarction/metabolism* ; Myocardial Reperfusion Injury/metabolism* ; NAD/metabolism* ; Rats ; Rats, Sprague-Dawley ; Sevoflurane/metabolism* ; Sirtuin 3/metabolism* ; Voltage-Dependent Anion Channel 1/metabolism*