Project Details
Projekt
The role of neurpopeptide Y in the arcuate nucleus of the hypothalamus in the regulation of energy expenditure and the involvment of its peripherally expressed receptor type-1 in the regulation of energy homeostasis in mice
Applicant
Dr. Giacomo Mancini
Subject Area
Endocrinology, Diabetology, Metabolism
Term
from 2012 to 2015
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 231922378
Aim 1: Does NPY deletion in different neuron populations of the arc effect energy balance and cellular fuel selection?Body composition (whole body lean and fat mass), energy expenditure and physical activity in the conditional KO and control mice will be examined by indirect calorimetry at 9 weeks of age as well as at the end of the study at 16 weeks of age. Upon completion of the study plasma, brown adipose tissue (BAT) and white adipose tissue (WAT), liver and muscle will be dissected and the expression patterns/activity levels of various key regulators involved in mitochondrial function and thermogenesis in relevant tissues, including mitochondrial respiratory chain complexes (IV), citrate synthase, peroxisome proliferator-activated receptor ý co-activator (PGC-1a), uncoupling protein-1 (UCP-1) will be analyzed by real time PCR, Western blot analysis and/or enzyme activity assay. To verify whether differences in cellular fuel selection are present, we will analyze regulators involved in lipid oxidation such as carnitine palmitoyltransferase-1 (CPT-1), beta-hydroxyacyl CoA dehydrogenase (b-HAD) and medium-chain acyl-CoA dehydrogenase (MCAD) in several organs, such as liver, WAT, muscle. Furthermore, serum will be collected and the analysis of an extensive panel of hormones involved in the regulation of metabolism will be carried out. Does NPY deletion in different neuron populations of the arc affect energy expenditure via regulation of hypothalamic peptides?In order to see if any changes in energy expenditure can be attributed to changes in expression patterns and levels of hypothalamic peptides, brains from these mice will also be collected and mRNA expression levels of different peptides will be evaluated by using in situ hybridization. Particular emphasis will be given to the analysis of the mRNA expression levels in the Arc of POMC and CART, the opposing neurotransmitters to NPY and AGRP. Aim 2. To determine the contribution of peripheral Y1 receptors to the regulation of energy homeostasis.Does peripherally deletion of Y1 receptor effect energy balance and cellular fuel selection? By using a tamoxifen-inducuble mouse line, conditional Y1 knockout mice will be analyzed on SD conditions similarly to what described in Aim1.Does peripherally deletion of Y1 receptor protects against diet-induced obesity? In order to determine the effect of tissue specific Y1-receptor deletion in an obese context, a second set of mice will be analyzed in the same way but under high fat feeding conditions. The same parameters will be analyzed as described above. It is important to test these animals also under these conditions, as it will demonstrate which Y1 expressing tissue is most affected by high calorie and high fat intake.
DFG Programme
Research Fellowships
International Connection
Australia, USA
