Nicotinamide riboside supplementation confers marginal metabolic benefits in obese mice without remodeling the muscle acetyl-proteome

Abstract

Summary Nicotinamide riboside supplements (NRS) have been touted as a nutraceutical that promotes cardiometabolic and musculoskeletal health by enhancing nicotinamide adenine dinucleotide (NAD + ) biosynthesis, mitochondrial function, and/or the activities of NAD-dependent sirtuin deacetylase enzymes. This investigation examined the impact of NRS on whole body energy homeostasis, skeletal muscle mitochondrial function, and corresponding shifts in the acetyl-lysine proteome, in the context of diet-induced obesity using C57BL/6NJ mice. The study also included a genetically modified mouse model that imposes greater demand on sirtuin flux and associated NAD + consumption, specifically within muscle tissues. In general, whole body glucose control was marginally improved by NRS when administered at the midpoint of a chronic high-fat diet, but not when given as a preventative therapy upon initiation of the diet. Contrary to anticipated outcomes, the study produced little evidence that NRS increases tissue NAD + levels, augments mitochondrial function, and/or mitigates diet-induced hyperacetylation of the skeletal muscle proteome.

Proteomics and phosphoproteomics datasets of a muscle-specific STIM1 loss-of-function mouse model

“…Upon completion of the search in PD2.5, The “Protein” and “Peptide Isoforms” tabs were exported from the .pdResult file as tab-delimited .txt files. Subsequent analysis used custom R scripts (doi: 10.5281/zenodo.6226588 ), modified from previous code [11] for use in R (version 4.0.5) in conjunction with Rstudio [12] . First, the phosphopeptide and protein abundance data were normalized to correct for any subtle (and unintended) deviations in equal amounts of peptide on each TMT channel in the input fraction, as described previously [13] , [14] .…”

Balancing NAD+ deficits with nicotinamide riboside: therapeutic possibilities and limitations

“…The protection of NR against diet-induced metabolic damage, however, has not been universally observed in the mouse studies carried out to this date. Recent works have reported either very marginal or no effects of NR on glucose metabolism, hepatic lipid accumulation or energy expenditure in diverse C57Bl/6 mouse strains submitted to HFD [206][207][208]. The reasons for these discrepancies are unclear but might be related to some important aspects beyond the small differences between the intervention designs.…”

“…First, in the initial reports where NR protected against diet-induced obesity, NR was administered as a trifluoromethanesulfonate (triflate) salt, mixed with food at an approximate dose of 400 mg/kg/day [ 80 , 152 ]. Triflate salts, however, are not considered as pharmaceutically acceptable for human use, which led to the development of the chloride salts that have been used in the most recent studies, where NR supplementation has often led to more modest [ 207 ] or no [ 206 , 208 ] effects on glucose homeostasis at various doses. A second factor that could play a major role are differences in animal housing conditions.…”

“…Additional preclinical studies will be needed to understand the variables influencing the therapeutic potential of NR in situations of metabolic disease. [198,199] • Approximately 1 g/kg/day of NR led to impaired glucose tolerance and WAT inflammation in mice [200] • Similar toxicology profile of NR and NAM in rodents [201] • No adverse effects with NR administration up to 2 g/day [153,[202][203][204][205] METABOLIC DISORDERS (I): GLUCOSE HOMEOSTASIS • NR prevented and/or treated diet-induced glucose intolerance in some [80,152], but not all studies [206][207][208] • NR improved glucose homeostasis in mice treated with a high-fat diet (HFD) and streptozotocin (STZ) [84] • NMN, which can be dephophorylated to NR, improved diet-induced glucose intolerance [74] • NR supplementation (1-2 g/day, for 6 and 12 weeks, respectively) failed to improve insulin sensitivity or influence glucose metabolism in overweight/ obese pre-diabetic patients [202,209,210] • NMN supplementation (250 mg/day for 10 weeks) improved insulin sensitivity in overweight/obese pre-diabetic postmenopausal women [211] METABOLIC DISORDERS (II):…”

“…MUSCLE PERFORMANCE • NR had no impact on exercise performance or muscle mitochondrial content in mice fed a regular diet [152,215] • No alterations in the skeletal muscle acetyl-proteome after NR treatment [207] • NR prevented the decline in muscle mitochondrial function triggered by chronic high-fat feeding [152] • Acute (2 h) or short-term (7 days) NR supplementation did not influence muscle performance or response to exercise in healthy young individuals [216,217] • No effect of NR supplementation on muscle mitochondrial content and respiratory capacity in overweight or obese pre-diabetic individuals [218,210] AGE-RELATED DECLINE (I): CARDIOVASCULAR FUNCTION • NR improved cardiac NAD + levels, cardiac function and premature death in a mouse model of altered LMNA function [219] • NR attenuated the development of heart failure in models of dilated cardiomyopathy or transverse aorta constriction, as well as in response to pressure overload. [94,220] • NR reduced the levels of circulating pro-inflammatory cytokines in patients with Stage D heart failure [221] • No change in cardiovascular parameters, but reduced systemic inflammation in elderly [222] • NR supplementation reduced some parameters linked to hypertension [205] AGE-RELATED DECLINE (II):…”