Project description:Adipose, once considered an inert storage depot, is now known to be an active endocrine tissue involved in total body homeostasis and metabolism, which exerts effects on multiple systems including food intake, immune function, and blood glucose regulation. Adipose tissue depots are known to have unique metabolic and gene expression profiles in vivo and when cultured in vitro. Differences in adipose tissue depot function could be important in determining chronic disease risk. Few comparisons of depot gene expression have been performed in the dog. Utilizing microarray technology, our objective was to identify differentially expressed genes and enriched functional pathways between subcutaneous and gonadal adipose of lean and obese dogs. Subcutaneous and gonadal adipose tissue samples were collected from 9 intact female beagles (4 yr-old; 4 lean controls; 5 obese ad libitum-fed) after 24 wk of ad libitum feeding.
Project description:Adipose, once considered an inert storage depot, is now known to be an active endocrine tissue involved in total body homeostasis and metabolism, which exerts effects on multiple systems including food intake, immune function, and blood glucose regulation. Adipose tissue depots are known to have unique metabolic and gene expression profiles in vivo and when cultured in vitro. Differences in adipose tissue depot function could be important in determining chronic disease risk. Few comparisons of depot gene expression have been performed in the dog. Utilizing microarray technology, our objective was to identify differentially expressed genes and enriched functional pathways between subcutaneous and gonadal adipose of lean and obese dogs.
Project description:Comparative oncology is a developing research discipline that is being used to assist our understanding of human neoplastic diseases. Companion canines are a preferred animal oncology model due to spontaneous tumor development and similarity to human disease at the pathophysiological level. We use a paired RNA sequencing (RNA-Seq)/microarray analysis of a set of four normal canine lymph nodes and ten canine lymphoma fine needle aspirates to identify technical biases and variation between the technologies and convergence on biological disease pathways. Surrogate Variable Analysis (SVA) provides a formal multivariate analysis of the combined RNA-Seq/microarray data set. Applying SVA to the data allows us to decompose variation into contributions associated with transcript abundance, differences between the technology, and latent variation within each technology. A substantial and highly statistically significant component of the variation reflects transcript abundance, and RNA-Seq proved more sensitive for detection of transcripts expressed at low levels. Latent random variation among RNA-Seq samples is also distinct in character from that impacting microarray samples. In particular, we observed variation between RNA-Seq samples that reflects transcript GC content. Platform-independent variable decomposition without a priori knowledge of the sources of variation using SVA represents a generalizable method for accomplishing cross-platform data analysis. We identified genes differentially expressed between normal lymph nodes of disease free dogs and a subset of the diseased dogs diagnosed with B-cell lymphoma using each technology. There is statistically significant overlap between the RNA-Seq and microarray sets of differentially expressed genes. Analysis of overlapping genes in the context of biological systems suggests elevated expression and activity of PI3K signaling in B-cell lymphoma biopsies compared with normal biopsies, consistent with literature describing successful use of drugs targeting this pathway in lymphomas.
Project description:Comparative oncology is a developing research discipline that is being used to assist our understanding of human neoplastic diseases. Companion canines are a preferred animal oncology model due to spontaneous tumor development and similarity to human disease at the pathophysiological level. We use a paired RNA sequencing (RNA-Seq)/microarray analysis of a set of four normal canine lymph nodes and ten canine lymphoma fine needle aspirates to identify technical biases and variation between the technologies and convergence on biological disease pathways. Surrogate Variable Analysis (SVA) provides a formal multivariate analysis of the combined RNA-Seq/microarray data set. Applying SVA to the data allows us to decompose variation into contributions associated with transcript abundance, differences between the technology, and latent variation within each technology. A substantial and highly statistically significant component of the variation reflects transcript abundance, and RNA-Seq proved more sensitive for detection of transcripts expressed at low levels. Latent random variation among RNA-Seq samples is also distinct in character from that impacting microarray samples. In particular, we observed variation between RNA-Seq samples that reflects transcript GC content. Platform-independent variable decomposition without a priori knowledge of the sources of variation using SVA represents a generalizable method for accomplishing cross-platform data analysis. We identified genes differentially expressed between normal lymph nodes of disease free dogs and a subset of the diseased dogs diagnosed with B-cell lymphoma using each technology. There is statistically significant overlap between the RNA-Seq and microarray sets of differentially expressed genes. Analysis of overlapping genes in the context of biological systems suggests elevated expression and activity of PI3K signaling in B-cell lymphoma biopsies compared with normal biopsies, consistent with literature describing successful use of drugs targeting this pathway in lymphomas. RNA was extracted from 10 lymphoma fine needle aspirates attained from companion canines. 4 normal lymph node samples were obtained from a Beagle breeding colony at Pfizer, including two samples that were taken from the same dog but different lymph nodes. This Series represents the Affymetrix gene expression only, not RNA-Seq referenced above. RNA-Seq data have been submitted to SRA as SRA059558.
Project description:Obesity is a heterogeneous conditions comprising obese individuals with metabolic disorders (termed metabolically unhealthy obese; MUO) and obese individuals who are metabolically healthy (termed metabolically healthy obese; MHO). We used microarrays to examine differences in subcutaneous adipose tissue gene expression from lean healthy (LH), metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO) individuals. Subcutaneous adipose tissue samples from the periumbilical region were obtained under local anesthesia and after an overnight fast. 50-100 mg of adipose tissue was homogenized and total RNA was extracted after homogenisation in TRIzol reagent using a tissue homogenizer.
Project description:Adipocytes isolated from lean and obese postmenopausal women with no significant differences in metabolic syndrome parameters demonstrate changes in multiple inflammatory, metabolic and structural gene families. Purified adipocyte samples were isolated from subcutaneous adipose tissue surgical biopsies of 7 obese (BMI>30) and 7 lean (BMI<25) postmenoposal women and gene expression was quantified with Agilent-014850, 4X44K human whole genome platform arrays (GPL6480)
Project description:Obesity is a heterogeneous conditions comprising obese individuals with metabolic disorders (termed metabolically unhealthy obese; MUO) and obese individuals who are metabolically healthy (termed metabolically healthy obese; MHO). We used microarrays to examine differences in subcutaneous adipose tissue gene expression from lean healthy (LH), metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO) individuals.
Project description:Individualized analysis through expression profiling of 20,000 probes in 28 tissue samples evaluated in subcutaneous and omental adipose tissue obtained during surgical intervention in non-obese and obese patients. Patients consisted of men and women of varying body size (lean to severely obese). Samples were collected at the time of operation in the fasting state. Samples consisted of subcutaneous and omental adipose tissue as well as a blood sample from lean and obese men and women removed in the fasting state at the time of surgery.