Neonatal starvation response and developmental changes in gene expression revealed by hypothalamic expression profiling

We performed gene expression microarray analysis of the hypothalamic response to starvation in neonatal wild-type mice, and in Snord116del mice that are a mouse model for PWS. This study is motivated by the neonatal feeding problems observed in several genetic diseases including Prader-Willi syndrome (PWS). Later in life, individuals with PWS develop hyperphagia and obesity due to lack of appetite control. We hypothesize that failure to thrive in infancy and later-onset hyperphagia may be related and could be due to a defect in the hypothalamus. In this study, we performed gene expression microarray analysis of the hypothalamic response to starvation in neonatal wild-type mice, and in Snord116del mice that are a mouse model for PWS. The neonatal starvation response was dramatically different from that reported in adult rodents. Genes that are affected by adult starvation are not changed in the hypothalamus of 5 day-old pups that were starved for 6 hrs. Unlike in adult rodents, expression levels of Nanos2 and Pdk4 were increased, and those of Pgpep1, Ndph, Brms1l, Mett10d, and Snx1 were decreased after fasting. In addition, we compared hypothalamic gene expression profiles at days 5 and 13 to document developmental changes. Notably, the gene expression profiles of Snord116del deletion mice and wild-type littermates were very similar at both postnatal days 5 and 13, and after starvation. We compared hypothalamic RNA between Snord116del mice with wild type (C57BL/6J) littermates at P5 and P13, with or without fasting treatment. We are particularly interested in the following comparisons: Comparison 1: wild type vs. PWS deletion in P5 non-starved mice; Comparison 2: wild type vs. PWS deletion in P5 fasting mice; Comparison 3: non-starved vs. fasting in P5 wild type mice; Comparison 4: non-starved vs. fasting in P5 PWS deletion mice; Comparison 5: wild type vs. PWD deletion in P13 non-starved mice; Comparison 6: P5 wild type vs. P13 wild type mice;