Lingual CD36 and nutritional status differentially regulate fat preference in obesity-prone and obesity-resistant rats

Abstract

Lingual fatty acid receptors (i.e. CD36) mediate the orosensory perception of fat/fatty acids and may contribute to the susceptibility to develop obesity. The current study tested the hypothesis that fat/fatty acid preference in obesity-prone (OP, Osborne-Mendel) and obesity-resistant (OR, S5B/Pl) rats is mediated by nutritional status and lingual CD36. To determine if nutritional status affected linoleic acid (LA) preference in OP and OR rats, rats were either fasted overnight or fed a high fat diet (60% kcal from fat). In OR rats, fasting increased the preference for higher concentrations of LA (1.0%), while consumption of a high fat diet decreased LA preference. In OP rats, fasting increased the preference for lower concentrations of LA (0.25%), however high fat diet consumption did not alter LA preference. To determine if lingual CD36 mediated the effects of an overnight fast on LA preference, the expression of lingual CD36 mRNA was assessed and the effect of lingual application of CD36 siRNA on LA preference was determined. Fasting increased lingual CD36 mRNA expression in OR rats, but failed to alter lingual CD36 mRNA in OP rats. Following an overnight fast, application of lingual CD36 siRNA led to a decrease in LA preference in OR, but not OP rats. Lingual application of CD36 siRNA was also used to determine if lingual CD36 mediated the intake and preference for a high fat diet in OP and OR rats. CD36 siRNA decreased the preference and intake of high fat diet in OR rats, but not OP rats. The results from this study suggest that the dysregulation of lingual CD36 in OP rats is a potential factor leading to increased fat intake and fat preference and an enhanced susceptibility to develop obesity.

High fat diet consumption differentially affects adipose tissue inflammation and adipocyte size in obesity-prone and obesity-resistant rats

“…The current study examined strain and HFD-induced differences in visceral and subcutaneous fat inflammation and adipocyte size in two rat models that differ in their susceptibility to develop obesity. OP rats are prone to developing obesity, consume more HFD, gain more weight when consuming a HFD, and have more visceral adiposity and total body adiposity than OR rats 13 , 16 , 17 , 33 , 39 – 41 . We hypothesized that OP rats would exhibit increased visceral adipose tissue inflammation and adipocyte hypertrophy compared to OR rats and that these effects would be exacerbated by chronic consumption of HFD.…”

“…When given a choice between a high fat (HFD) and a low fat diet (LFD), OP rats consume more calories from fat than carbohydrates, consume more HFD and subsequently, gain more body mass and fat mass in comparison to OR rats. 33 , 39 . OP rats exhibit inherent and HFD-induced increases in visceral adiposity, body adiposity and skeletal muscle lipid accumulation, compared to OR rats 13 , 16 , 17 , 40 , 41 .…”

Free‐Living Responses in Energy Balance to Short‐Term Overfeeding in Adults Differing in Propensity for Obesity

“…Some individuals seem more susceptible to weight gain (i.e., those with obesity proneness [OP]) than others (i.e., those with obesity resistance [OR]). These OP and OR phenotypes have been well studied in rodent models ; however, less work has been done in human subjects. Our Energy Adaptations over Time Study (EATS) was designed to measure the adaptive responses to short‐term (3 days) OF that may protect from or promote weight gain in adults self‐identified as having OP or OR based on personal and family history .…”

Orlistat mouth rinse: Using the tongue to deliver antiobesity medication in a double‐blind randomized crossover pilot trial

“…11,12 Lingual CD36 has been proposed as the primary fat taste receptor, although other receptors, including G-protein-coupled receptor (GPR)120, are thought to mediate the orosensory perception of dietary fat. [11][12][13][14][15][16] Studies investigating the role of lingual fat sensors on fat preference and intake in preclinical and clinical models report individual variability in the orosensory perception of dietary fat, leading to differences in the preference for and sensitivity to fat. Obesity-prone rats exhibit a high preference for fat, but a low lingual sensitivity to fat, suggesting an impairment or desensitization of the fat signal.…”