Project description:High fat diet (HF) rodent models have contributed significantly to the dissection of the pathophysiology of the insulin resistance syndrome, but their phenotype varies distinctly between different studies. Here, we have analyzed gene expression patterns in livers of animals fed with different HF with varying fatty acid compositions. Keywords: diet-gene interaction
Project description:MicroRNAs are important negative regulators of protein coding gene expression, and have been studied intensively over the last few years. To this purpose, different measurement platforms to determine their RNA abundance levels in biological samples have been developed. In this study, we have systematically compared 12 commercially available microRNA expression platforms by measuring an identical set of 20 standardized positive and negative control samples, including human universal reference RNA, human brain RNA and titrations thereof, human serum samples, and synthetic spikes from homologous microRNA family members. We developed novel quality metrics in order to objectively assess platform performance of very different technologies such as small RNA sequencing, RT-qPCR and (microarray) hybridization. We assessed reproducibility, sensitivity, quantitative performance, and specificity. The results indicate that each method has its strengths and weaknesses, which helps guiding informed selection of a quantitative microRNA gene expression platform in function of particular study goals.
Project description:Wild type (a/a) agouti mouse dams were randomized to one of three diets (control, mediterranean, western) two weeks prior to pairing with an agouti (Avy/a) sire. Diet exposure continued through pregnancy and lactation. All pups were weaned onto the control diet and then followed for metabolic phenotyping measures to 10 months of age. Comprehensive phenotyping (body composition, CLAMS, blood draw) was completed at 2, 4, and 8 months, with an OGTT at 8 months. Weekly weights were also recorded. The study examines whether prenatal dietary exposure to high fat diets (HFD) and bisphenol a (BPA, those groups will not be tested in this pilot) impacts metabolic programming in offspring as measured by hepatic steatosis, serum hormone levels, and epigenetic changes in hepatic lipid metabolism genes.
Project description:The ketone body β-hydroxybutyrate (BHB) is produced during dietary restriction, fasting, and exercise. A ketogenic diet (KD) results in long-term production of BHB outside of these contexts. We sought to determine a protein-matched, non-obese ketogenic diet (KD) would affect the longevity and healthspan of C57BL/6 male mice. We find that feeding KD every-other-week to prevent obesity (cyclic KD) reduces mid-life mortality but does not affect maximum lifespan. Similar feeding of a non-ketogenic high-fat/low-carbohydrate (HF) diet may have an intermediate effect on mortality. Cyclic KD improves memory performance in old age, while modestly improving composite measures of healthspan. RNAseq gene expression analysis identifies down-regulation of insulin, TOR, and fatty acid synthesis pathways as possible longevity mechanisms common to KD and HF. However, up-regulation of fasting-related PPARα target genes is unique to KD, consistent across tissues, and preserved in old age, suggesting a mechanism for an incremental benefit from KD. In all, we show that a non-obese ketogenic diet improves survival, memory, and healthspan into old age. These gene expression studies were carried out on 12 month-old male C56BL/6 mice from the NIA Aged Rodent Colony, habituated to AIN-93M control diet and then either maintained on this diet or switched for one week to a 75% kcal fat non-ketogenic high-fat diet or a 90% kcal fat ketogenic diet (all diets with 10% kcal from carbohydrates). Tissues were harvested in the middle of the nighttime feeding period (MN-3am).