Effect of nicotinamide riboside on lipid metabolism and gut microflora-bile acid axis in alcohol-exposed mice

The Prevalence of Pretransplant Frailty and Mental Distress in Hematopoietic Cell Transplantation and Association with Clinical Outcomes

Frailty is a phenotype of decreased physiologic reserve associated with increased risk of toxicities and nonrelapse mortality (NRM) in hematopoietic cell transplant (HCT) recipients. The incidence, predictors, and adverse effects of pre-HCT frailty are not well known. We evaluated the association of pre-HCT frailty, defined using Fried's criteria, with age and baseline characteristics in patients ≥18 years undergoing autologous (auto) or allogeneic (allo) HCT for hematological malignancies. Assessments were performed as part of routine pre-HCT evaluations and then retrospectively analyzed. We additionally investigated the association of mental health distress indicators with frailty and the association between frailty and transplant outcomes including NRM and overall survival (OS) plus healthcare utilization. Patients undergoing HCT for hematological malignancies were analyzed (total n = 300; 162 auto, 138 allo). The overall prevalence of frailty was 18%, 21.7% among alloHCT, and 14.8% among autoHCT recipients, with similar distributions of frailty domains. Logistic regression analysis of the overall cohort revealed that older age was associated with an increased risk of frailty (odds ratio [OR] 1.37, 95% confidence interval [CI] [1.02-1.82]; P = 0.04). AlloHCT (OR 2.03, CI [1.07-3.84]; P = .03), and patient health questionnaire-9 (PHQ-9) (health depression) score ≥10 (OR 6.28, CI 1.93-20.43; P < .01) were each independently associated with pre-HCT frailty. In alloHCT patients, older age (OR 1.44, CI [1.00-2.06]; P = .05) was the only significant risk factor for pre-HCT frailty, while for autoHCT patients, only a higher PHQ-9 score was associated with frailty (OR 6.43, CI [1.34-30.82]; P = .02). For the whole cohort OS at 1 year was lower in frail recipients at 83% (95% CI, 70-91%) versus 92% (95% CI, 88-95%) in nonfrail (P = .04); with multivariate analysis showing higher risk of death in the frail group (hazard ratio [HR] 2.31, CI 0.97-5.46; P = .06). In the alloHCT cohort, multivariate analysis showed greater 1-year mortality in frail recipients (HR 2.55, CI [0.99-6.56]; P = .053). In the alloHCT recipients, we observed a 1-year NRM of 20% in frail patients versus 9% in nonfrail, and multivariate analysis showed a marginally higher risk of NRM in the frail group (HR 2.70, CI 0.90-8.10; P = .08). Frailty was not associated with higher risk of relapse in alloHCT or autoHCT recipients. Frail alloHCT patients experienced a longer initial hospital stay following HCT compared to nonfrail recipients (P < .01). We observed a high prevalence of pre-HCT frailty across all age groups, and identify older age is a risk factor for frailty, particularly in alloHCT recipients. Frailty is associated with a greater risk of NRM and lower survival which needs investigation in a larger cohort. Frailty associates with greater HCT complexity suggesting a need for early assessments and targeted interventions for this vulnerable population. Our findings suggest the utility of frailty and mental distress screening along with multidisciplinary interventions in pre-HCT to limit the morbidity of HCT.

Regulation of intestinal microflora and metabolites of Penthorum chinense Pursh on alcoholic liver disease

Introduction: Alcoholic liver disease (ALD) was the second leading cause of liver injury. Penthorum chinense Pursh (GHC) is an important Miao ethnic drug of traditional Chinese medicine for the treatment of liver disease, but the pathogenesis is not clear. Aim of the study: To analysis the intestinal microflora and metabolic pathway of GHC on ALD mice. Methods: An HPLC-QTOF-MS method was used to identified the components from GHC extract, firstly. 60 mice were divided into six groups including blank group, model group, positive group and GHC groups (0.29, 0.87 and 2.61 g/kg). ALD mice was treated with GHC for 12 days. ALT, AST, TC and TG in serum were determined, liver index and pathological analysis were achieved. 16S rRNA gene sequencing was used to detect the intestinal microbial diversity. Finally, UPLC-QTOF-MS was used to analysis the metabolic pathways. Results: 38 ingredients were identified in GHC extract. Compared with the model group, liver index of the positive group and GHC (2.61 g/kg) group was significantly reduced. Compared with the model group, contents of ALT, AST, TC and TG of GHC groups reduced in a dose-dependent manner. Intestinal microbial diversity analysis indicated that Chao1, Observed species, Pielou_e, and Shannon indexes in GHC group (2.61 g/kg) were lower than those in model group. Principal coordinate analysis indicated that the intestinal microbial composition between blank group and model group, the model group and GHC (2.61 g/kg) group changed significantly. Compared with the model group, proportion of Firmicutes decreased, and the proportion of Bacteroidetes increased significantly in GHC group, which were 50.84% and 40.15%. The more prominent bacteria in the GHC group were odoribacteraceae, turicibacter, deferribacteraceae, and the intestinal beneficial symbiotic bacteria mucispirillum. Metabolic analysis indicated that, compared with blank group, 90 metabolites in model group changed significantly, and 68 metabolites were significantly callback in GHC group. Discussion: GHC has a therapeutic effect on ALD by regulating intestinal flora imbalance and metabolic pathways including Glycine, serine and threonine metabolism, Glutathione metabolism, Arginine and proline metabolism, Alanine, aspartate and glutamate metabolism, Butanoate metabolism and primary bile acid biosynthesis.

Untargeted Metabolomics Analysis Reveals Toxicity Based on the Sex and Sexual Maturity of Single Low-Dose DEHP Exposure

Di-(2-Ethylhexyl) phthalate (DEHP) is a prevalent environmental endocrine disruptor that affects homeostasis, reproduction, and developmental processes. The effects of DEHP have been shown to differ based on sex and sexual maturity. This study examines the metabolic profiles of mature adult rats from both sexes, aged 10 weeks, and adolescent female rats, aged 6 weeks, following a single 5 mg/kg of body weight DEHP oral administration. An untargeted metabolomic analysis was conducted on urine samples collected at multiple times to discern potential sex- and maturity-specific DEHP toxicities. Various multivariate statistical analyses were employed to identify the relevant metabolites. The findings revealed disruptions to the steroid hormone and primary bile acid biosynthesis. Notably, DEHP exposure increased hyocholic, muricholic, and ketodeoxycholic acids in male rats. Moreover, DEHP exposure was linked to heart, liver, and kidney damage, as indicated by increased plasma GOT1 levels when compared to the levels before DEHP exposure. This study provides detailed insights into the unique mechanisms triggered by DEHP exposure concerning sex and sexual maturity, emphasizing significant distinctions in lipid metabolic profiles across the different groups. This study results deepens our understanding of the health risks linked to DEHP, informing future risk assessments and policy decisions.

Nicotinamide Riboside, a Promising Vitamin B3 Derivative for Healthy Aging and Longevity: Current Research and Perspectives

Many studies have suggested that the oxidized form of nicotinamide adenine dinucleotide (NAD+) is involved in an extensive spectrum of human pathologies, including neurodegenerative disorders, cardiomyopathy, obesity, and diabetes. Further, healthy aging and longevity appear to be closely related to NAD+ and its related metabolites, including nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN). As a dietary supplement, NR appears to be well tolerated, having better pharmacodynamics and greater potency. Unfortunately, NR is a reactive molecule, often unstable during its manufacturing, transport, and storage. Recently, work related to prebiotic chemistry discovered that NR borate is considerably more stable than NR itself. However, immediately upon consumption, the borate dissociates from the NR borate and is lost in the body through dilution and binding to other species, notably carbohydrates such as fructose and glucose. The NR left behind is expected to behave pharmacologically in ways identical to NR itself. This review provides a comprehensive summary (through Q1 of 2023) of the literature that makes the case for the consumption of NR as a dietary supplement. It then summarizes the challenges of delivering quality NR to consumers using standard synthesis, manufacture, shipping, and storage approaches. It concludes by outlining the advantages of NR borate in these processes.

Nicotinamide riboside improves muscle mitochondrial biogenesis, satellite cell differentiation, and gut microbiota in a twin study

Nicotinamide adenine dinucleotide (NAD+) precursor nicotinamide riboside (NR) has emerged as a promising compound to improve obesity-associated mitochondrial dysfunction and metabolic syndrome in mice. However, most short-term clinical trials conducted so far have not reported positive outcomes. Therefore, we aimed to determine whether long-term NR supplementation boosts mitochondrial biogenesis and metabolic health in humans. Twenty body mass index (BMI)-discordant monozygotic twin pairs were supplemented with an escalating dose of NR (250 to 1000 mg/day) for 5 months. NR improved systemic NAD+ metabolism, muscle mitochondrial number, myoblast differentiation, and gut microbiota composition in both cotwins. NR also showed a capacity to modulate epigenetic control of gene expression in muscle and adipose tissue in both cotwins. However, NR did not ameliorate adiposity or metabolic health. Overall, our results suggest that NR acts as a potent modifier of NAD+ metabolism, muscle mitochondrial biogenesis and stem cell function, gut microbiota, and DNA methylation in humans irrespective of BMI.

Antioxidant effects of Se-glutathione peroxidase in alcoholic liver disease

Oxidative damage induced by ethanol and its metabolites is one of the factors that fuels the development of alcoholic liver disease (ALD). Selenium (Se) is an effective cofactor for glutathione peroxidase (GPx), and has antioxidant effects that improve ALD. In patients with ALD, ethanol-induced oxidative damage inhibits the synthesis of related Se-containing proteins such as: selenoprotein P (Sepp1), albumin (ALB), and GPx in the liver, thus decreasing the overall Se level in patients. Both Se deficiency and excess can affect the expression of GPx, resulting in damage to the antioxidant defense system. This damage enhances oxidative stress by increasing the levels of reactive oxygen species (ROS) in the body, which aggravates the inflammatory response, lipid metabolism disorder, and lipid peroxidation and worsens ALD symptoms. A cascade of oxidative damages caused by ALD will deplete selenium deposition in the body, stimulate the expression of Gpx1, Sepp1, and Gpx4, and thus mobilize systemic selenoproteins, which can restore GPx activity in the hepatocytes of ALD patients, reduce the levels of reactive oxygen species and alleviate oxidative stress, the inflammatory response, lipid metabolism disorder, and lipid peroxidation, thus helping to mitigate ALD. This review provides a reference for future ALD studies that evaluate the regulation of Se levels and contributes to studies on the potential pathological mechanisms of Se imbalance in ALD.

The gut microbiota–bile acid axis: A potential therapeutic target for liver fibrosis

Liver fibrosis involves the proliferation and deposition of extracellular matrix on liver tissues owing to various etiologies (including viral, alcohol, immune, and metabolic factors), ultimately leading to structural and functional abnormalities in the liver. If not effectively treated, liver fibrosis, a pivotal stage in the path to chronic liver disease, can progress to cirrhosis and eventually liver cancer; unfortunately, no specific clinical treatment for liver fibrosis has been established to date. In liver fibrosis cases, both the gut microbiota and bile acid metabolism are disrupted. As metabolites of the gut microbiota, bile acids have been linked to the progression of liver fibrosis via various pathways, thus implying that the gut microbiota–bile acid axis might play a critical role in the progression of liver fibrosis and could be a target for its reversal. Therefore, in this review, we examined the involvement of the gut microbiota–bile acid axis in liver fibrosis progression to the end of discovering new targets for the prevention, diagnosis, and therapy of chronic liver diseases, including liver fibrosis.

Nicotinamide Riboside Supplementation to Suckling Male Mice Improves Lipid and Energy Metabolism in Skeletal Muscle and Liver in Adulthood

Nicotinamide riboside, an NAD⁺ precursor, has been attracting a lot of attention in recent years due to its potential benefits against multiple metabolic complications and age-related disorders related to NAD⁺ decline in tissues. The metabolic programming activity of NR supplementation in early-life stages is much less known. Here, we studied the long-term programming effects of mild NR supplementation during the suckling period on lipid and oxidative metabolism in skeletal muscle and liver tissues using an animal model. Suckling male mice received a daily oral dose of NR or vehicle (water) from day 2 to 20 of age, were weaned at day 21 onto a chow diet, and at day 90 were distributed to either a high-fat diet (HFD) or a normal-fat diet for 10 weeks. Compared to controls, NR-treated mice were protected against HFD-induced triacylglycerol accumulation in skeletal muscle and displayed lower triacylglycerol levels and steatosis degree in the liver and distinct capacities for fat oxidation and decreased lipogenesis in both tissues, paralleling signs of enhanced sirtuin 1 and AMP-dependent protein kinase signaling. These pre-clinical findings suggest that mild NR supplementation in early postnatal life beneficially impacts lipid and energy metabolism in skeletal muscle and liver in adulthood, serving as a potential preventive strategy against obesity-related disorders characterized by ectopic lipid accumulation.

Nicotinamide (niacin) supplement increases lipid metabolism and ROS‐induced energy disruption in triple‐negative breast cancer: potential for drug repositioning as an anti‐tumor agent

Metabolic dysregulation is an important hallmark of cancer. Nicotinamide (NAM), a water‐soluble amide form of niacin (vitamin B3), is currently available as a supplement for maintaining general physiologic functions. NAM is a crucial regulator of mitochondrial metabolism and redox reactions. In this study, we aimed to identify the mechanistic link between NAM‐induced metabolic regulation and the therapeutic efficacy of NAM in triple‐negative breast cancer (TNBC). The combined analysis using multiomics systems biology showed that NAM decreased mitochondrial membrane potential and ATP production, but increased the activities of reverse electron transport (RET), fatty acid β‐oxidation and glycerophospholipid/sphingolipid metabolic pathways in TNBC, collectively leading to an increase in the levels of reactive oxygen species (ROS). The increased ROS levels triggered apoptosis and suppressed tumour growth and metastasis of TNBC in both human organoids and xenograft mouse models. Our results showed that NAM treatment leads to cancer cell death in TNBC via mitochondrial dysfunction and activation of ROS by bifurcating metabolic pathways (RET and lipid metabolism); this provides insights into the repositioning of NAM supplement as a next‐generation anti‐metabolic agent for TNBC treatment.

Metabolic Disease, NAD Metabolism, Nicotinamide Riboside, and the Gut Microbiome: Connecting the Dots from the Gut to Physiology

The effort to use nutrients as interventions to treat human disease has been important to medicine. A current example in this vein pertains to NAD⁺ boosters, such as nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN), which are in many clinical trials in a variety of disease conditions. Independent laboratories have shown that ingested NR (or NMN) has mitigating effects on metabolic syndrome in mice. V. V. Lozada-Fernández, O. deLeon, S. L. Kellogg, F. L. Saravia, et al. (mSystems 7:e00230-21, 2022, https://doi.org/10.1128/mSystems.00230-21) show that NR shifts gut microbiome contents and that the transplantation of an NR-conditioned microbiome by fecal transfer reproduces some effects of NR in mice on a high-fat diet. The involvement of the gut microbiome as a factor in NR effects is linked to changes to the gut microbiome and its activity to transform NR and downstream catabolites. This commentary draws attention to these findings and focuses on some puzzling aspects of NAD⁺ boosters, exploring the still murky interactions between NAD⁺ metabolism, energy homeostasis, and the gut microbiome.

NAD+ and NAFLD - caution, causality and careful optimism

The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing worldwide, and new treatments are sorely needed. Nicotinamide adenine dinucleotide (NAD⁺ ) has been proposed as a potential target to prevent and reverse NAFLD. NAD⁺ is an important redox factor for energy metabolism and is used as a substrate by a range of enzymes, including sirtuins (SIRT), which regulates histone acetylation, transcription factor activity and mitochondrial function. NAD⁺ is also a precursor for reduced nicotinamide adenine dinucleotide phosphate (NADPH), which is an important component of the antioxidant defense system. NAD⁺ precursors such as nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) are available as over-the-counter dietary supplements, and oral supplementation with these precursors increases hepatic NAD⁺ levels and prevents hepatic lipid accumulation in pre-clinical models of NAFLD. NAD⁺ precursors have also been found to improve hepatic mitochondrial function and decrease oxidative stress in pre-clinical NAFLD models. NAD⁺ repletion also prevents NAFLD progression to non-alcoholic steatohepatitis (NASH), as NAD⁺ precursor supplementation is associated with decreased hepatic stellate cell activation, and decreased fibrosis. However, initial clinical trials have only shown modest effects when NAD⁺ precursors were administrated to people with obesity. We review the available pre-clinical investigations of NAD⁺ supplementation for targeting NAFLD, and discuss how data from the first clinical trials can be reconciled with observations from preclinical research.