Thursday, 11 September 2014

Omega-3 fatty acids rescues Fragile X phenotypes in Fmr1-Ko mice

"These results demonstrate that n-3 PUFAs dietary supplementation, although not a panacea, has a considerable therapeutic value for FXS [Fragile X syndrome] and potentially for ASD [autism spectrum disorder], suggesting a major mediating role of neuroinflammatory mechanisms".

A view @ Wikipedia 
That was the conclusion reached by Susanna Pietropaolo and colleagues [1] who "evaluated the impact of n-3 PUFA dietary supplementation in a mouse model of fragile X syndrome (FXS), i.e., a major developmental disease and the most frequent monogenic cause of ASD". Looking at the Fmr1-KO mouse model of FXS, a mouse specifically bred to mimic the silencing of the FMR1 gene noted in FXS (see here) with onwards adverse effects for the production of FMRP, researchers looked at what happened when diets were "enriched or not with n-3 PUFAs from weaning until adulthood when they were tested for multiple FXS-like behaviors". The results seemed to indicate that "n-3 PUFA supplementation rescued most of the behavioral abnormalities displayed by Fmr1-KO mice, including alterations in emotionality, social interaction and non-spatial memory, although not their deficits in social recognition and spatial memory". Neuroinflammatory imbalances noted in the knock-out mice were also positively affected by omega-3 supplementation.

I don't need to remind you that the Pietropaolo study was a study of mice and one needs to be quite careful about extrapolating animal results when it comes to humans. That being said, given the quite extensive work that has been done on FXS and the detailing of it's molecular background, one might assume that the current results are treated with a little less scepticism than in relation to other more idiopathic 'types' of autism. Still, proper trials with people are indicated as per other research.

Omega-3 fatty acids have been discussed before on this blog with autism in mind (see here). The collected literature on their usefulness as supplements for autism is rather mixed at present [2] despite some emerging evidence on their involvement in various biological processes in cases of autism (see here). That being said, I'm not getting too down on omega-3 fatty acids in light of some associations being made with specific skills over and above any condition-specific relationship and some new light being shed on their use in other conditions [3]. I'm yet to find anything like an experimental trial of fatty acids in real people with FXS but did chance(!) upon the study by Lachance and colleagues [4] (open-access) talking about the use of fenretinide (N-(4-hydroxyphenyl) retinamide (4HPR)) in the test-tube and effects "associated with the normalization of arachidonic acid/docosahexaenoic acid ratio in macrophages". The effect talked about translates as a down-regulation in the "production of arachidonic acid (AA), a pro-inflammatory omega-6 polyunsaturated fatty acid, and to increase levels of omega-3 polyunsaturated docosahexaenoic acid (DHA), which has an anti-inflammatory effect". Mmm... possibly some new targets to replace quite a few disappointments when it comes to FXS therapeutics (see here).

Music to close. Fontella Bass and Rescue Me.

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[1] Pietropaolo S. et al. Dietary supplementation of omega-3 fatty acids rescues fragile X phenotypes in Fmr1-Ko mice. Psychoneuroendocrinology. 2014 Jul 9;49C:119-129.

[2] James S. et al. Omega-3 fatty acids supplementation for autism spectrum disorders (ASD). Cochrane Database Syst Rev. 2011 Nov 9;(11):CD007992.

[3] Hawkey E. & Nigg JT. Omega-3 fatty acid and ADHD: Blood level analysis and meta-analytic extension of supplementation trials. Clin Psychol Rev. 2014 Jun 2;34(6):496-505.

[4] Lachance C. et al. Fenretinide corrects the imbalance between omega-6 to omega-3 polyunsaturated fatty acids and inhibits macrophage inflammatory mediators via the ERK pathway. PLoS One. 2013 Sep 12;8(9):e74875.

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ResearchBlogging.org Pietropaolo S, Goubran MG, Joffre C, Aubert A, Lemaire-Mayo V, Crusio WE, & Layé S (2014). Dietary supplementation of omega-3 fatty acids rescues fragile X phenotypes in Fmr1-Ko mice. Psychoneuroendocrinology, 49C, 119-129 PMID: 25080404