Transcriptomic analysis of circumvallate papillae (CVP) from lean and DIO mice

Diet-induced obesity (DIO) is associated with a decreased oral fat detection in rodents. This blunted gustatory detection has been explained by an impairment of the lipid-mediated signaling in taste bud cells (TBC). However, factors responsible for this defect remain elusive. To better understand the mechanisms involved, circumvallate papillae from Lean, DIO and former DIO mice were analyzed with a transcriptomic approach. [using Agilent Sureprint G3 Mouse microarrays (8x60K, design 028005)] After a one-week acclimatization period, the mice (C57Bl6/j) were fed ad libitum either a standard laboratory chow (4RF21, Mucedola, Italy; containing 3% fat, w/w) or an obesogenic diet high fat diet, rich in saturated fatty acids described in (Chevrot et al, 2013). Some DIO mice were calorie restricted (= 60% energy of ad libitum energy intake).CVP from control and DIO mice were isolated according to the procedure described in (Laugerette et al, 2005). Briefly, lingual epithelium was separated from connective tissue by enzymatic dissociation (elastase and dispase mixture, 2 mg/ml each in Tyrode buffer: 140 mM NaCl, 5 mM KCl, 10 mM HEPES, 1 mM CaCl2, 10 mM glucose, 1 mM MgCl2, 10 mM Na pyruvate, pH 7.4) and the papilla was dissected under a binocular microscope. CVP were snap-frozen in liquid nitrogen then stored at -80°C. Plasma was obtained after centrifugation of blood (5000 g for 10 min, 4°C).