Project description:We are using ACI and BN rats, which differ markedly in their susceptibility to 17beta-Estradiol (E2)-induced mammary cancer, to identify genetic variants and environmental factors that determine mammary cancer susceptibility. The objective of this study was to characterize the cellular and molecular responses to E2 in the mammary glands of ACI and BN rats to identify qualitative and quantitative phenotypes that associate with and/or may confer differences in susceptibility to mammary cancer. Female ACI and BN rats were treated with E2 for 1, 3 or 12 weeks and cell proliferation, apoptosis, differentiation and gene expression were evaluated. The luminal epithelium of ACI rats exhibited a rapid and sustained proliferative response to E2. By contrast, the proliferative response exhibited by the mammary epithelium of BN rats was restrained and transitory. Moreover, the epithelium of BN rats appeared to undergo differentiation in response to E2, as evidenced by production of milk proteins as well as luminal ectasia and associated changes in the extracellular matrix (ECM). Marked differences in expression of genes that encode proteins with well-defined roles in mammary gland development (Pgr, Wnt4, Tnfsf11, Prlr, Stat5a, Areg, Gata3), differentiation and milk production (Lcn2, Spp1), regulation of extracellular environment (Mmp7, Mmp9), and cell-cell or cell-ECM interactions (Cd44, Cd24, Cd52) were observed. We propose that these cellular and molecular phenotypes are heritable and may underlie, at least in part, the differences in mammary cancer susceptibility exhibited by ACI and BN rats. Two groups of 17beta-estradiol treated female rats were compared. Five ACI and five BN rats were treated with 17beta-estradiol for 12 weeks. Total RNA was isolated from the mammary glands of these animals, labeled, and hybridized to Affymetrix Rat Genome 230 2.0 Arrays (Affymetrix Inc.). Significantly differentially expressed genes were found between these groups.

Project description:To examine the influence cellular and genetics on the procainamide-induced autoimmune response in spleens we compared rats that are genetically Th2-predisposed (Brown Norway), Th1-predisposed (Lewis) or not genetically predisposed (Sprague Dawley). Rats were treated with procainamide three times per week. From the second week, blood samples were taken once a week for antinuclear antibody (ANA) detection. At 56d after treatment, rats were sacrificed and spleens samples were collected for microarray test and histopathology examination. Frequencies of T cell subsets and B cells in rat spleen were measured to assess the effects on splenocyte. Also, 12 serum cytokines/chemokines were determined to explored the Th1/Th2 cytokine pattern after treatment. We found that ANA were makedly elevated in BN and SD rats, while the elevated appeared earlier in BN rats, and the magnitude of its increase were much higher than that of SD rats. There was no marked change in serum ANA in Lewis rats. Histopathological analysis indicated that spleen weight increased significantly both in BN and SD rats after stimulated with procainamide. No significant changes in spleen weight and lesions were observed in Lewis rats. We also found the percentage of CD86 positive cells in spleen of BN rats was significantly increased, while the percentage of CD4+CD25+ cells was decreased in BN rats. In addition, percentage of CD11b/c positive cells were decreased, and the levels of Th-2 (IL-10), Th-1 type cytokine (IFN-γ) and chemokine (IL-1β) in serum were markedly elevated both in BN and SD rats after treatment. Th-2 type cytokine (IL-4, IL-6) in serum were markedly increased only in BN rats. Furthermore, similar immune mechanisms were found in BN and SD rat, and the altered genes were mainly associated in immune response, and inflammatory response. However, the number of differentially expressed genes (DEGs) in BN rats was higher than that in SD rats. Overall, we revealed significant differences in response to autoimmunity induced by procainamide among three strains rats, the BN rats was the most sensitive one, SD rats exhibited less sensitive while Lewis resistance to procainamide. Much more pronounced of Th2-type responses and more complex DEGs involved in immune regulation and response in BN rats might contribute to its susceptible to drug-induced lupus erythematosus. Moreover, similar immune mechanisms were found between BN and SD rat, which suggesting that these changes would served as the potential bridge biomarkers to predict drug-induced autoimmune reactions among species. The results may also provide a scientic basis for the high sensitivity of BN rats in prediction immunotoxicity in preclinical studies.

Project description:Studies of normal human mammary gland development and function have mostly relied on cell culture, limited surgical specimens, and rodent models. Although RNA extracted from human milk has been used to assay the mammary transcriptome non-invasively, the transcriptome derived from the milk fat layer has not been compared with the mammary-derived transcriptome nor have sources of RNA been quantified in milk. In this study the effects of milk collection and processing on RNA quality and origin were assessed in humans and rhesus macaques. Total RNA in milk was quantitated in acridine orange-stained milk using an automated whole slide scanner and custom-built Globulator software. Total RNA extracted from milk fat, cells in milk, and mammary biopsies of lactating rhesus macaques were compared using RNA sequencing and analysis. Compared with human milk, milk from macaques contained similar amounts of RNA-containing cytoplasmic crescents, but more cells. Total RNA extracted from milk fractions was also evaluated for factors that affect RNA quality. Degradation of RNA extracted from human milk fat was positively correlated with geographic distance from collection site, storage time, and sample type. There were no differences in RNA degradation in macaque milk collected after 10 min or 4 hr accumulation, suggesting that degradation of RNA extracted from milk fat may not occur in the mammary gland. Using RNA-Seq, RNA extracted from macaque milk fat and cells in milk more accurately represented RNA from mammary epithelial cells (cells that produce milk) than did RNA from mammary tissue. Mammary epithelium-specific transcripts were more abundant in macaque milk fat whereas adipose or stroma-specific transcripts were more abundant in mammary tissue. Functional analyses confirmed the validity of milk as a source of RNA from mammary epithelial cells. Analysis of highly abundant putative microRNAs in macaque milk fat revealed a potentially novel non-coding RNA species that is conserved in humans. RNA extracted from the milk fat during lactation accurately portrayed the RNA profile of milk-producing mammary epithelial cells. However, this sample type clearly requires protocols that minimize RNA degradation.

Project description:Studies of normal human mammary gland development and function have mostly relied on cell culture, limited surgical specimens, and rodent models. Although RNA extracted from human milk has been used to assay the mammary transcriptome non-invasively, the transcriptome derived from the milk fat layer has not been compared with the mammary-derived transcriptome nor have sources of RNA been quantified in milk. In this study the effects of milk collection and processing on RNA quality and origin were assessed in humans and rhesus macaques. Total RNA in milk was quantitated in acridine orange-stained milk using an automated whole slide scanner and custom-built Globulator software. Total RNA extracted from milk fat, cells in milk, and mammary biopsies of lactating rhesus macaques were compared using RNA sequencing and analysis. Compared with human milk, milk from macaques contained similar amounts of RNA-containing cytoplasmic crescents, but more cells. Total RNA extracted from milk fractions was also evaluated for factors that affect RNA quality. Degradation of RNA extracted from human milk fat was positively correlated with geographic distance from collection site, storage time, and sample type. There were no differences in RNA degradation in macaque milk collected after 10 min or 4 hr accumulation, suggesting that degradation of RNA extracted from milk fat may not occur in the mammary gland. Using RNA-Seq, RNA extracted from macaque milk fat and cells in milk more accurately represented RNA from mammary epithelial cells (cells that produce milk) than did RNA from mammary tissue. Mammary epithelium-specific transcripts were more abundant in macaque milk fat whereas adipose or stroma-specific transcripts were more abundant in mammary tissue. Functional analyses confirmed the validity of milk as a source of RNA from mammary epithelial cells. Analysis of highly abundant putative microRNAs in macaque milk fat revealed a potentially novel non-coding RNA species that is conserved in humans. RNA extracted from the milk fat during lactation accurately portrayed the RNA profile of milk-producing mammary epithelial cells. However, this sample type clearly requires protocols that minimize RNA degradation. Transcript profiles from milk cells, milk fat, and mammary tissue from 6 lactating rhesus macaques at 30 and 90 days lactation; 34 samples run in triplicate

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Association of Cellular and Molecular Responses in the Rat Mammary Gland to 17beta-Estradiol with Susceptibility to Mammary Cancer

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