Project description:Impairments in ATP production and transport in renal proximal tubule cells (RPTCs) result in obesity-induced chronic kidney disease (CKD), manifested by kidney dysfunction, inflammation, adiposity, and fibrosis. Here we assessed the role of adenine nucleotide transporter 2 (ANT2), the main regulator of cellular ATP content in RPTCs, in the development of obesity-induced CKD and its metabolic abnormalities. Obese RPTC-ANT2-/- mice exhibited normal renal morphology, function, and lack of kidney adiposity and fibrosis as well as an improvement in whole-body energy metabolism, manifested by normal glucose and lipid homeostasis and reduced hepatic steatosis. ANT2-depleted RPTCs rewired their primary metabolic program from oxidizing fatty acids as a primary energy source toward aerobic glycolysis, mediated via the testis-selective ANT4. We propose that RPTC-ANT2 plays an important role in the development of obesity-induced CKD, and that its nullification triggers mitochondrial protection, RPTC cellular survival, kidney preservation, and improvements in systemic metabolism.
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:The health effect of dietary fat has been one of the most vexing issues in the nutrition field. Few animal studies have examined the impact of high-fat diets on lifespan by controlling energy intake. In this study, we found that compared to a normal diet, an isocaloric high-fat diet (IHF) significantly prolonged lifespan by decreasing the profiles of free fatty acids (FFAs) in serum and multiple tissues by downregulating FFAs anabolism and upregulating catabolism pathways in rats and flies. Proteomics analysis in rats identified PPRC1 as a key protein that was significantly upregulated by nearly 2-fold by IHF, and among the FFAs, only palmitic acid (PA) was robustly and negatively associated with the expression of PPRC1. Using PPRC1 transgenic RNAi/overexpression flies and in vitro experiments, we further demonstrated that IHF significantly reduced PA, which could upregulate PPRC1 through PPARG, resulting in improvements in oxidative stress and inflammation and prolonging lifespan.
Project description:Younger age and obesity increase the incidence and rates of metastasis of triple-negative breast cancer (TNBC), an aggressive subtype of breast cancer. The tissue microenvironment, specifically the extracellular matrix (ECM), is known to promote tumor invasion and metastasis. We sought to characterize the effect of both age and obesity on the ECM of mammary fat pads. We used a diet-induced obesity (DIO) model where 10-week-old female mice were fed a high-fat diet (HFD) for 16 weeks or a control chow diet (CD) where time points were every 4 weeks to monitor age and obesity HFD progression. We isolated the mammary fat pads to characterize the ECM at each time point. Utilizing proteomics, we found that the early stages of obesity were sufficient to induce distinct differences in the ECM composition of mammary fat pads that promote TNBC cell invasion. ECM proteins previously implicated in driving TNBC invasion Collagen IV and Collagen VI, were enriched with weight gain. Together these data implicate ECM changes in the primary tumor microenvironment as mechanisms by which age and obesity contribute to breast cancer progression.
Project description:This dataset contains proteomic data from mice with high or low weight gain in response to a high fat diet. Both host and microbial proteins are present. In the supplemental, there are also tables and supplementary files that can be used for replicating the bioinformatic analysis.
Abstract:
Consumption of refined high-fat, low-fiber diets promotes development of obesity and its associated consequences. While genetics play an important role in dictating susceptibility to such obesogenic diets, mice with nearly uniform genetics exhibit marked heterogeneity in their extent of obesity in response to such diets. This suggests non-genetic determinants play a role in diet-induced obesity. Hence, we sought to identify parameters that predict, and/or correlate with, development of obesity in response to an obesogenic diet. We assayed behavior, metabolic parameters, inflammatory markers/cytokines, microbiota composition, and the fecal metaproteome, in a cohort of mice (n=50) prior to, and the 8 weeks following, administration of an obesogenic high-fat low-fiber diet. Neither behavioral testing nor quantitation of inflammatory markers broadly predicted severity of diet-induced obesity. Although, the small subset of mice that exhibited basal elevations in serum IL-6 (n=5) were among the more obese mice in the cohort. While fecal microbiota composition changed markedly in response to the obesogenic diet, it lacked the ability to predict which mice were relative prone or resistant to obesity. In contrast, fecal metaproteome analysis revealed functional and taxonomic differences among the proteins associated with proneness to obesity. Targeted interrogation of microbiota composition data successfully validated the taxonomic differences seen in the metaproteome. While future work will be needed to determine the breadth of applicability of these associations to other cohorts of animals and humans, this study nonetheless highlights the potential power of gut microbial proteins to predict and perhaps impact development of obesity.