Nitrate attenuates high fat diet-induced glucose intolerance in association with reduced epididymal adipose tissue inflammation and mitochondrial reactive oxygen species emission.

Autor: Brunetta HS; Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada.; Department of Physiological Sciences, Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil., Politis-Barber V; Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada., Petrick HL; Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada., Dennis KMJH; Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada., Kirsh AJ; Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada., Barbeau PA; Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada., Nunes EA; Department of Physiological Sciences, Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil., Holloway GP; Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada.
Jazyk: angličtina
Zdroj: The Journal of physiology [J Physiol] 2020 Aug; Vol. 598 (16), pp. 3357-3371. Date of Electronic Publication: 2020 Jun 16.
DOI: 10.1113/JP279455
Abstrakt: Key Points: Dietary nitrate is a prominent therapeutic strategy to mitigate some metabolic deleterious effects related to obesity. Mitochondrial dysfunction is causally linked to adipose tissue inflammation and insulin resistance. Whole-body glucose tolerance is prevented by nitrate independent of body weight and energy expenditure. Dietary nitrate reduces epididymal adipose tissue inflammation and mitochondrial reactive oxygen species emission while preserving insulin signalling. Metabolic beneficial effects of nitrate consumption are associated with improvements in mitochondrial redox balance in hypertrophic adipose tissue.
Abstract: Evidence has accumulated to indicate that dietary nitrate alters energy expenditure and the metabolic derangements associated with a high fat diet (HFD), but the mechanism(s) of action remain incompletely elucidated. Therefore, we aimed to determine if dietary nitrate (4 mm sodium nitrate via drinking water) could prevent HFD-mediated glucose intolerance in association with improved mitochondrial bioenergetics within both white (WAT) and brown (BAT) adipose tissue in mice. HFD feeding caused glucose intolerance (P < 0.05) and increased body weight. As a result of higher body weight, energy expenditure increased proportionally. HFD-fed mice displayed greater mitochondrial uncoupling and a twofold increase in uncoupling protein 1 content within BAT. Within epididymal white adipose tissue (eWAT), HFD increased cell size (i.e. hypertrophy), mitochondrial H 2 O 2 emission, oxidative stress, c-Jun N-terminal kinase phosphorylation and leucocyte infiltration, and induced insulin resistance. Remarkably, dietary nitrate consumption attenuated and/or mitigated all these responses, including rendering mitochondria more coupled within BAT, and normalizing mitochondrial H 2 O 2 emission and insulin-mediated Akt-Thr308 phosphorylation within eWAT. Intriguingly, the positive effects of dietary nitrate appear to be independent of eWAT mitochondrial respiratory capacity and content. Altogether, these data suggest that dietary nitrate attenuates the development of HFD-induced insulin resistance in association with attenuating WAT inflammation and redox balance, independent of changes in either WAT or BAT mitochondrial respiratory capacity/content.
(© 2020 The Authors. The Journal of Physiology © 2020 The Physiological Society.)
Databáze: MEDLINE
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