Metabolic abnormalities and hypoleptinemia in <script type="math/tex">\alpha</script>-synuclein A53T mutant mice

Rothman, Sarah M.; Griffioen, Kathleen J.; Fishbein, Kenneth W.; Spencer, Richard G.; Makrogiannis, Sokratis; Cong, Wei-na; Martin, Bronwen; Mattson, Mark P.

doi:10.1016/J.NEUROBIOLAGING.2013.10.088

Title

Metabolic abnormalities and hypoleptinemia in $\alpha$ -synuclein A53T mutant mice

Author

Rothman, Sarah M.

Griffioen, Kathleen J.

Fishbein, Kenneth W.

Spencer, Richard G.

Makrogiannis, Sokratis

Cong, Wei-na

Martin, Bronwen

Mattson, Mark P.

Abstract

Parkinsons disease (PD) patients frequently display loss of body fat mass and increased energy expenditure, and several studies have outlined a relationship between these metabolic abnormalities and disease severity, yet energy metabolism is largely unstudied in mouse models of PD. Here we characterize metabolic and physiologic responses to a high calorie diet (HCD) in mice expressing in neurons a mutant form of human α-synuclein (A53T) that causes dominantly inherited familial forms of the disease. A53T (SNCA) and wild type (WT) littermate mice were placed on a HCD for 12 weeks and evaluated for weight gain, food intake, body fat, blood plasma leptin, hunger, glucose tolerance, and energy expenditure. Results were compared to both SNCA and WT mice on a control diet. Despite consuming similar amounts of food, WT mice gained up to 66% of their original body weight on a HCD whereas SNCA mice gained only 17%. Further, after 12 weeks on a HCD, MRI analysis revealed that WT mice had significantly greater total and visceral body fat compared to SNCA mice (p<0.007). At 24 weeks of age SNCA mice displayed significantly increased hunger compared to WT (p<0.03). At 36 weeks of age, SNCA mice displayed significant hypoleptinemia compared to WT, both on a normal diet and a HCD (p<0.03). The HCD induced insulin insensitivity in WT, but not SNCA mice, as indicated by an oral glucose tolerance test. Finally, SNCA mice displayed greater energy expenditure compared to WT, as measured in a Comprehensive Lab Animal Monitoring System, after 12 weeks on a HCD. Thus, SNCA mice are resistant to HCD-induced obesity and insulin resistance and display reduced body fat, increased hunger, hypoleptinemia and increased energy expenditure. Our findings reveal a profile of metabolic dysfunction in a mouse model of PD that is similar to that of human PD patients, thus providing evidence that α-synuclein pathology is sufficient to drive such metabolic abnormalities and providing an animal model for discovery of the underlying mechanisms and potential therapeutic interventions.

Language

English

Source (journal)

Neurobiology of aging. - Fayetteville, N.Y.

Publication

Fayetteville, N.Y. : 2014

ISSN

0197-4580

DOI

10.1016/J.NEUROBIOLAGING.2013.10.088

Volume/pages

35 :5 (2014) , p. 1153-1161