Project description:Rodents respond to chronic high fat diet in at least two ways: some of them may readily gain body weight and become obese (termed obesity-prone), and others may not (termed obesity-resistant). An integrated approach of transcript and metabolic profiling of obesity-prone and obesity-resistant rats has been conducted, showing significantly different transcript and metabolic profiles in the two phenotypes. The major transcriptional differences involved hepatic fatty acid metabolism and ketogenesis in response to 16 weeks of high fat diet. At the same time, the different metabolic profiles (in liver tissue extracts, serum, and urine) between the two phenotypes could be ascribed to the corresponding pathways identified with multivariate statistical analysis, including fatty acid metabolism, Krebs cycle, and amino acid metabolism. The integration of results from both transcript and metabolic profiling revealed the different responses to dietary intervention of the two phenotypes and the physiological basis of susceptibility to metabolic disease in obesity-prone rats from a systematic view.
Project description:Background: Post-menopausal obesity is an established risk factor for breast cancer. Consumption of diets high in fat is known to be highly correlated with obesity. In this, we sought to evaluate the interaction(s) between high fat diet, weight gain and mammary carcinogenesis using an obese-resistant and obese-prone rat model with direct correlates to human disease. Methods: Female obese-prone (OP) and obese-resistant (OR) weanling rats were placed on either a low fat (10% kcal) or a high fat (39% kcal) n-6 polyunsaturated (PUFA) safflower diet for 30 days. At post natal day (PND) 50, global gene expression profiling was performed on microdissected mammary epithlelium from one cohort of rats and another cohort of rats were given a single oral gavage of either 7,12-dimethylbenz[a]anthracene (DMBA at 14 mg/kg) or vehicle. Rats were then maintained on the diets and body weights, food consumption and development of mammary lesions were monitored weekly. Results: The DMBA-treated OR rats on the 39% safflower diet had significantly greater incidence of ductal carcinoma-in-situ (DCIS) lesions and significantly greater DCIS multiplicity than DMBA-treated OR rats on the 10% safflower diet. These differences were not seen in the OP strain. Gene expression analysis of mammary ductal epithelium from OR rats on the high fat diet showed significant upregulation of proliferation-related genes compared to those consuming the low fat safflower diet. Again, these differences were not seen in the OP strain. Conclusion: Our findings indicate that consumption of high fat safflower diet enhances mammary carcinogenesis in an OR rat strain through increased proliferation of mammary epithelium at the time of exposure, but not in the OP rat strain. Thus, the diet-induced increase in sensitivity was strain-specific and independent of weight gain or obesity level. Female obese-prone (OP) and obese-resistant (OR) weanling rats were placed on either a low fat (10% kcal) or a high fat (39% kcal) n-6 polyunsaturated (PUFA) safflower diet for 30 days. At post natal day (PND) 50, global gene expression profiling was performed on microdissected mammary epithlelium from one cohort of rats and another cohort of rats were given a single oral gavage of either 7,12-dimethylbenz[a]anthracene (DMBA at 14 mg/kg) or vehicle. Rats were then maintained on the diets and body weights, food consumption and development of mammary lesions were monitored weekly.
Project description:Background: Post-menopausal obesity is an established risk factor for breast cancer. Consumption of diets high in fat is known to be highly correlated with obesity. In this, we sought to evaluate the interaction(s) between high fat diet, weight gain and mammary carcinogenesis using an obese-resistant and obese-prone rat model with direct correlates to human disease. Methods: Female obese-prone (OP) and obese-resistant (OR) weanling rats were placed on either a low fat (10% kcal) or a high fat (39% kcal) n-6 polyunsaturated (PUFA) safflower diet for 30 days. At post natal day (PND) 50, global gene expression profiling was performed on microdissected mammary epithlelium from one cohort of rats and another cohort of rats were given a single oral gavage of either 7,12-dimethylbenz[a]anthracene (DMBA at 14 mg/kg) or vehicle. Rats were then maintained on the diets and body weights, food consumption and development of mammary lesions were monitored weekly. Results: The DMBA-treated OR rats on the 39% safflower diet had significantly greater incidence of ductal carcinoma-in-situ (DCIS) lesions and significantly greater DCIS multiplicity than DMBA-treated OR rats on the 10% safflower diet. These differences were not seen in the OP strain. Gene expression analysis of mammary ductal epithelium from OR rats on the high fat diet showed significant upregulation of proliferation-related genes compared to those consuming the low fat safflower diet. Again, these differences were not seen in the OP strain. Conclusion: Our findings indicate that consumption of high fat safflower diet enhances mammary carcinogenesis in an OR rat strain through increased proliferation of mammary epithelium at the time of exposure, but not in the OP rat strain. Thus, the diet-induced increase in sensitivity was strain-specific and independent of weight gain or obesity level.
Project description:As patients with heart failure with preserved ejection fraction (HFpEF) present with multiple comorbidities, we hypothesized, that metabolic syndrome in aging animals could lead to the development of diastolic dysfunction and HFpEF. HFpEF is a common complex morbid syndrome for which there are currently little evidence-based therapies. Obesity-prone rats were exposed to high-fat diet and compared to obesity-resistant rats fed with standard chow. Phenotyping of metabolic syndrome, associated with echocardiographic and cardiac hemodynamic measurements, was performed after 4 and 12 months. Blood and myocardial tissue sampling were performed for pathobiological evaluation. High-fat diet in obesity-prone rats elicited metabolic syndrome, characterized by increased body and abdominal fat weights, glucose intolerance and hyperlipidemia, as well as increased left ventricular (LV) systolic pressure (after 12 months). This was associated with LV diastolic dysfunction (assessed by increased LV end-diastolic pressure) and pulmonary hypertension (assessed by increased right ventricular systolic pressure). Echocardiography revealed significant concentric LV hypertrophy, while LV ejection fraction was preserved. LV remodeling was associated with cardiomyocyte hypertrophy, as well as myocardial and perivascular fibrosis. Circulating levels of soluble ST2 markedly increased in rats with HFpEF, while plasma NT-proBNP levels decreased. RNA-sequencing analysis identified clusters of genes implicated in fatty acid metabolism and calcium-dependent contraction as upregulated pathways in the myocardium of rats with HFpEF. High-fat diet during 12 months in obesity-prone rats led to the development of a relevant preclinical model of HFpEF with multiple comorbidities, suitable for investigating novel therapeutic interventions.
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.