In Contrast to Dietary Restriction, Application of Resveratrol in Mice Does not Alter Mouse Major Urinary Protein Expression.

Kathrin Pallauf,Gerald Rimbach,Dawn Chin,Ilka Günther

doi:10.3390/nu12030815

Abstract

Resveratrol (RSV) supplementation in mice has been discussed as partly mimicking the beneficial effects of dietary restriction (DR). However, data on putative benefits from resveratrol application in mice and other model organisms including humans is contradictory. Mouse major urinary proteins (MUPs) are a family of proteins that are expressed in rodent liver and secreted via urine. Impacting (mating) behavior and pheromone communication, they are severely down-regulated upon DR. We carried out two studies in C57BL/6Rj mice where RSV was either supplemented via diet or injected intraperitoneally for 8 weeks. Contrary to −40% DR, RSV did not decrease total MUP protein expression or Mup (amongst others Mup3, Mup5, Mup6, Mup15, and Mup20) mRNA levels in mouse liver when compared to ad-libitum (AL)-fed controls. Since inhibitory glucocorticoid response elements can be found in Mup promoters, we also measured glucocorticoid receptor (GR) levels in nuclear hepatic extracts. Consistent with differential MUP expression, we observed more nuclear GR in DR mice than in RSV-supplemented and AL control mice with no difference between RSV and AL. These findings point to the notion that, in mice, RSV does not mimic DR in terms of differential MUP expression.

Highlights

Mouse major urinary proteins (MUPs) are genes expressed in the liver of mice and excreted via urine [1]
Feed intake for the mice consuming RSV or control mice (CON) diets did not differ between the groups and was 3.0 g/ day for the i.p. mice and 2.7 g/day for the mice supplemented via diet
While the results for mouse urinary protein (Mup) expression were similar in both studies, we found a difference between trials when measuring Mup3 mRNA levels in dietary restriction (DR) compared to CON mice

Summary

Introduction

Mouse major urinary proteins (MUPs) are genes expressed in the liver (and to some extent in other tissues) of mice and excreted via urine [1]. As members of the lipocalin protein family, these gene products can function as carriers of pheromones, thereby stabilizing their olfactory potential [2,3]. There are 21 MUPs and most of them are very similar to each other. It seems that mice express different but fixed subsets of MUPs depending on their strain [10] with the amount but probably not the ratio of excreted protein, depending on the circumstances [11]

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Conclusion