Publications by authors named "Maria P Giner"

Article Synopsis
  • Mitochondrial dysfunction and low NAD levels are linked to aging and muscle loss (sarcopenia), but it's unclear if these issues come from local or systemic factors.
  • Research shows that trigonelline, a natural compound similar to nicotinic acid, positively affects NAD levels and muscle health across different species, including humans.
  • Trigonelline enhances mitochondrial function, reduces muscle wasting, and increases strength and lifespan, suggesting that dietary trigonelline could be a helpful strategy against age-related muscle decline.
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Nicotinamide riboside kinases (NRKs) control the conversion of dietary Nicotinamide Riboside (NR) to NAD, but little is known about their contribution to endogenous NAD turnover and muscle plasticity during skeletal muscle growth and remodeling. Using NRK1/2 double KO (NRKdKO) mice, we investigated the influence of NRKs on NAD metabolism and muscle homeostasis, and on the response to neurogenic muscle atrophy and regeneration following muscle injury. Muscles from NRKdKO animals have altered nicotinamide (NAM) salvage and a decrease in mitochondrial content.

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Through evolution, eukaryote organisms have developed the ability to use different molecules as independent precursors to generate nicotinamide adenine dinucleotide (NAD), an essential molecule for life. However, whether these different precursors act in an additive or complementary manner is not truly well understood. Here, we have evaluated how combinations of different NAD precursors influence intracellular NAD levels.

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Nicotinamide adenine dinucleotide (NAD) and its reduced form (NADH) are coenzymes employed in hundreds of metabolic reactions. NAD also serves as a substrate for enzymes such as sirtuins, poly(ADP-ribose) polymerases (PARPs) and ADP-ribosyl cyclases. Given the pivotal role of NAD(H) in health and disease, studying NAD metabolism has become essential to monitor genetic- and/or drug-induced perturbations related to metabolic status and diseases (such as ageing, cancer or obesity), and its possible therapies.

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This study evaluated the validity of nutrient and food group intakes estimated by an FFQ against biomarkers. A 71-item semiquantitative FFQ was administered to 210 Brazilian children and adolescents aged 9-13 years. Intakes were correlated with biomarkers in plasma and red blood cells.

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Summary: Nuclear magnetic resonance (NMR)-based metabolomics is widely used to obtain metabolic fingerprints of biological systems. While targeted workflows require previous knowledge of metabolites, prior to statistical analysis, untargeted approaches remain a challenge. Computational tools dealing with fully untargeted NMR-based metabolomics are still scarce or not user-friendly.

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Article Synopsis
  • Sarcopenia, a condition causing muscle wasting and weakness in older adults, is less understood compared to general muscle aging, affecting physical independence and survival.
  • A study analyzed muscle biopsies from 119 older men across Singapore, the UK, and Jamaica, finding that individuals with sarcopenia exhibit clear signs of mitochondrial dysfunction in their muscles.
  • Key indicators of this dysfunction include reduced signaling related to energy production, fewer mitochondria, diminished respiratory complex activity, and low levels of NAD, highlighting the critical role of mitochondrial metabolism in age-related muscle loss.
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Objective: A decay in intracellular NAD levels is one of the hallmarks of physiological decline in normal tissue functions. Accordingly, dietary supplementation with NAD precursors can prevent, alleviate, or even reverse multiple metabolic complications and age-related disorders in diverse model organisms. Within the constellation of NAD precursors, nicotinamide riboside (NR) has gained attention due to its potent NAD biosynthetic effects in vivo while lacking adverse clinical effects.

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Supplementation with the NAD precursor nicotinamide riboside (NR) ameliorates and prevents a broad array of metabolic and aging disorders in mice. However, little is known about the physiological role of endogenous NR metabolism. We have previously shown that NR kinase 1 (NRK1) is rate-limiting and essential for NR-induced NAD synthesis in hepatic cells.

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Although c-Myc is essential for melanocyte development, its role in cutaneous melanoma, the most aggressive skin cancer, is only partly understood. Here we used the mouse melanoma model to show that c-Myc is essential for tumor initiation, maintenance, and metastasis. c-Myc-expressing melanoma cells were preferentially found at metastatic sites, correlated with increased tumor aggressiveness and high tumor initiation potential.

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The Brazilian Healthy Eating Index-Revised (BHEI-R) can be used to determine overall dietary patterns. We assessed the BHEI-R scores in children and adolescents, aged from 9 to 13 years old, and associated its component scores with biomarkers of health and dietary exposure. Three 24-h recalls were used to generate BHEI-R.

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