modeling-hypoxiareoxygenation-injury-proximal-tubular-epithelial

Modeling Hypoxia/Reoxygenation Injury in Proximal Tubular Epithelial Cells

Kidney transplantation accounts for approximately 60%-65% of all transplanted solid organs. Most donor kidneys are obtained from deceased individuals, ...

Universidad Católica de Murcia

Dysregulation of nicotinamide adenine dinucleotide (NAD) homeostasis by increased activity of NAD consumers or reduced NAD biosynthesis plays an important role in the onset of prevalent, often age-related, diseases, such as diabetes, neuropathies or nephropathies. To counteract such dysregulation, NAD replenishment strategies can be used. Among these, administration of vitamin B derivatives (NAD precursors) has garnered attention in recent years. However, the high market price of these compounds and their limited availability, pose important limitations to their use in nutritional or biomedical applications. To overcome these limitations, we have designed an enzymatic method for the synthesis and purification of (1) the oxidized NAD precursors nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR), (2) their reduced forms NMNH and NRH, and (3) their deaminated forms nicotinic acid mononucleotide (NaMN) and nicotinic acid riboside (NaR). Starting from NAD or NADH as substrates, we use a combination of three highly overexpressed soluble recombinant enzymes; (a) a NAD+ pyrophosphatase, (b) an NMN deamidase, and (c) a 5'-nucleotidase, to produce these six precursors. Finally, we validate the activity of the enzymatically produced molecules as NAD enhancers in cell culture.

Biotechnological production of reduced and oxidized NAD precursors.

The degenerative processes that occur during aging increase the risk of disease and impaired health. Meanwhile, interventions that target aging to promote healthy longevity are gaining interest, both academically and in the public. While nutritional and physical interventions exist, efficacy is often difficult to determine. It is therefore imperative that an aging score measuring the biological aging process is available to the wider public. However, simple, interpret, and accessible biological aging scores are lacking. Here, we developed PhysiAge, a physiological aging score based on five accessible parameters that have influence on or reflect the aging process: (1) average daily step count, (2) blood glucose, (3) systolic blood pressure, (4) sex, and (5) age. Here, we found that compared to calendar age alone, PhysiAge better predicts mortality, as well as established muscle aging markers such as decrease in NAD levels, increase in oxidative stress, and decline in physical functioning. In order to demonstrate the usefulness of PhysiAge in identifying relevant factors associated with decelerated aging, we calculated PhysiAges for a cohort of aged individuals and obtained mass spectrometry-based blood plasma metabolomic profiles for each individual. Here, we identified a metabolic signature of decelerated aging, which included components of the TCA cycle, including malate, citrate, and isocitrate. Higher abundance of these metabolites was associated with decelerated aging, in line with supplementation studies in model organisms. PhysiAge represents an accessible way for people to track and intervene in their aging trajectories, and identifies a metabolic signature of decelerated aging in human blood plasma, which can be further studied for its causal involvement in human aging.

A metabolomic signature of decelerated physiological aging in human plasma.

Cardiorenal diseases represent a complex interplay between heart failure and renal dysfunction, being clinically classified as cardiorenal syndromes (CRS). Recently, the contributions of altered nicotinamide adenine dinucleotide (NAD) metabolism, through deficient NAD synthesis and/or elevated consumption, have proved to be decisive in the onset and progress of cardiorenal disease. NAD is a pivotal coenzyme in cellular metabolism, being significant in various signaling pathways, such as energy metabolism, DNA damage repair, gene expression, and stress response. Convincing evidence suggests that strategies designed to boost cellular NAD levels are a promising therapeutic option to address cardiovascular and renal disorders. Here, we review and discuss the implications of NAD metabolism in cardiorenal diseases, focusing on the propitious NAD boosting therapeutic strategies, based on the use of NAD precursors, poly(ADP-ribose) polymerase inhibitors, sirtuin activators, and other alternative approaches, such as CD38 blockade, nicotinamide phosphoribosyltransferase activation and combined interventions.

NAD enhancers as therapeutic agents in the cardiorenal axis.

Ageing leads to a gradual deterioration of the organs, with the brain being particularly susceptible, often leading to neurodegeneration. This process includes well-known changes such as tau hyperphosphorylation and beta-amyloid deposition, which are commonly associated with neurodegenerative diseases but are also present in ageing. These structures are triggered by earlier cellular changes such as energy depletion and impaired protein synthesis, both of which are essential for cell function. These changes may in part be induced by environmental pollution, which has been shown to accelerate these processes. Cold Atmospheric Plasma (CAP) or atmospheric pressure gas discharge plasmas have shown promise in activating the immune system and improving cellular function in vitro, although their effects at the organ level remain poorly understood. Our aim in this work is to investigate the effect of a device that combines CAP treatment with the effective removal of environmental nanoparticles, typical products of pollution, on the activity of aged mouse brains. The results showed an increase in energy capacity, a reduction in reticulum stress and an activation of cellular autophagic clearance, minimising aggresomes in the brain. This leads to a reduction in key markers of neurodegeneration such as tau hyperphosphorylation and beta-amyloid deposition, demonstrating the efficacy of the tested product at the brain level.

Combining Cold Atmospheric Plasma and Environmental Nanoparticle Removal Device Reduces Neurodegenerative Markers.

: The exposome, encompassing all environmental influences on health, plays a pivotal role in oxidative stress-related diseases. Negative air ions (NAIs), generated via cold atmospheric plasma (CAP), have been proposed as potential modulators of oxidative resilience. This study aims to investigate the metabolic adaptations induced by prolonged exposure to an NAI-enriched environment in mice, focusing on its effects in oxidative stress markers and energy metabolism in liver and blood. : Twenty male C57BL/6J mice were divided into four groups: two experimental groups exposed to NAI-enriched air generated by an Air Cold Atmospheric Plasma-Nanoparticle Removal (aCAP-NR) device for either 18 days (short-term, ST) or 28 days (long-term, LT), and two control groups without exposure. Targeted metabolomics was performed in whole blood and liver using ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS). Statistical and pathway analyses were conducted to assess metabolic alterations. : Metabolic profiling revealed significant shifts in oxidative stress-related pathways, including enhanced glutathione metabolism, reduced lipid peroxidation, and modulation of purine metabolism. Short-term exposure led to increased mitochondrial efficiency and energy homeostasis, while long-term exposure induced adaptive metabolic reprogramming, with higher inosine levels suggesting enhanced antioxidant and anti-inflammatory responses. No adverse effects on systemic or hepatic health markers were observed. : NAI exposure via aCAP-NR elicits a hormetic response, enhancing metabolic efficiency and resilience to oxidative stress. These findings suggest that controlled environmental enrichment with NAIs may serve as a novel non-invasive strategy for mitigating oxidative damage and improving metabolic health, as hormetic adaptative capacity and resilience to oxidative stress, warranting further translational research.

The Hormetic Adaptative Capacity and Resilience to Oxidative Stress Is Strengthened by Exposome Enrichment with Air Cold Atmospheric Plasma: A Metabolome Targeted Follow-Up Approach.

Beyond their classical functions as redox cofactors, recent fundamental and clinical research has expanded our understanding of the diverse roles of nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP) in signaling pathways, epigenetic regulation and energy homeostasis. Moreover, NAD and NADP influence numerous diseases as well as the processes of aging, and are emerging as targets for clinical intervention. Here, we summarize safety, bioavailability and efficacy data from NAD-related clinical trials, focusing on aging and neurodegenerative diseases. We discuss the established NAD precursors nicotinic acid and nicotinamide, newer compounds such as nicotinamide riboside and nicotinamide mononucleotide, and emerging precursors. We also discuss technological advances including in industrial-scale production and real-time detection, which are facilitating NAD research and clinical translation. Finally, we emphasize the need for further large-scale studies to determine optimal dose, administration routes and frequency, as well as long-term safety and interindividual variability in response.

Emerging strategies, applications and challenges of targeting NAD in the clinic.

Nicotinamide adenine dinucleotide (NAD) is an essential molecule involved in cellular metabolism, and its decline has been implicated in ageing and age-related disorders. However, evidence for an age-related decline in NAD levels in humans has been consistently observed only in a limited number of studies. Similarly, although preclinical studies support the idea that supplementation with NAD precursors is a promising therapeutic strategy to promote healthy ageing, human clinical trials have shown limited efficacy. Therefore, an increasing understanding of how NAD metabolism is affected in different tissues during disease and following NAD precursor supplementation is crucial to defining the therapeutic value of NAD-targeted therapies. In this Review, we evaluate the clinical evidence supporting the notion that NAD levels decline with age, as well as the tissue-specific effects of NAD precursor supplementation. Viewed in perspective, the published body of data on NAD dynamics in human tissues remains sparse, and the extrapolation of rodent-based data is not straightforward, underscoring the need for more clinical studies to gain deeper insights into systemic and tissue-specific NAD metabolism.

Article	Year
Biotechnological production of reduced and oxidized NAD precursors. Food research international (Ottawa, Ont.)\| PubMed ID: 36869544	2023
A metabolomic signature of decelerated physiological aging in human plasma. GeroScience\| PubMed ID: 37259015	2023
NAD enhancers as therapeutic agents in the cardiorenal axis. Cell communication and signaling : CCS\| PubMed ID: 39516787	2024
Combining Cold Atmospheric Plasma and Environmental Nanoparticle Removal Device Reduces Neurodegenerative Markers. International journal of molecular sciences\| PubMed ID: 39684696	2024
The Hormetic Adaptative Capacity and Resilience to Oxidative Stress Is Strengthened by Exposome Enrichment with Air Cold Atmospheric Plasma: A Metabolome Targeted Follow-Up Approach. Biomedicines\| PubMed ID: 40299663	2025
Emerging strategies, applications and challenges of targeting NAD in the clinic. Nature aging\| PubMed ID: 40926126	2025
NAD precursor supplementation in human ageing: clinical evidence and challenges. Nature metabolism\| PubMed ID: 41083806	2025

Ruben Zapata-Perez

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