Project description:The present study aimed at proposing a novel chemically-induced cirrhosis-associated rat hepatocarcinogenesis model, involving the characterization of histological, biochemical and molecular features. Male Wistar rats received a single dose of diethylnitrosamine (DEN, 200 mg/Kg body weight [b.wt.]), and were submitted to several cycles of thioacetamide (TAA, 200 mg/Kg b.wt.), during 23 weeks. Blood and liver were collected from untreated and DEN/TAA-treated groups. Liver samples were processed for global gene expression (cDNA microarray), histopathological (HE) and collagen content (picrosirius red) evaluations, immunohistochemical (Ki-67, GST-P and α-SMA), biochemical (catalase, glutathione peroxidase and glutathione-S-transferase) and gelatin zymography (MMP-2 and 9) analysis. Using a very stringent analysis (FDR<0.01 and fold change>3), gene expression array evidenced 359 differentially expressed genes upon DEN/TAA regimen. Gene Ontology and functional analyses showed several upregulated genes involved in extracellular matrix organization, mainly collagen type I α1 and 2 (Col1α1, Col1α2) and tissue inhibitor of metalloproteinase 1 and 2 (Timp1 and Timp2) genes. In addition, glutathione S-transferase, pi 1 and 2 (Gstp1 and Gstp2) genes were markedly upregulated. In contrast, functional analyses also revealed the downregulation of antioxidant response genes, as catalase, glutathione peroxidase 1 and glutathione S-transferase mu type 3 (Cat, Gpx1 and Gstm3). In agreement with gene expression data, our model presented extensive liver cirrhosis with increased α-SMA expression and collagen deposition, as well as marked development of preneoplastic GST-P positive hyperplastic lesions and some neoplasms. Besides, we observed a decrease in total glutathione peroxidase, total glutatione-S-tranferase and catalase activities. The characterization of a suitable cirrhosis-associated hepatocarcinogenesis model could provide insights into molecular characteristics of the human disease and be applied to evaluate potential preventive and therapeutic approaches.
Project description:In order to establish a rat embryonic stem cell transcriptome, mRNA from rESC cell line DAc8, the first male germline competent rat ESC line to be described and the first to be used to generate a knockout rat model was characterized using RNA sequencing (RNA-seq) analysis.
Project description:Major urinary proteins (MUP) are the major component of the urinary protein fraction in house mice (Mus spp.) and rats (Rattus spp.). The structure, polymorphism and functions of these lipocalins have been well described in the western European house mouse (Mus musculus domesticus), clarifying their role in semiochemical communication. The complexity of these roles in the mouse raises the question of similar functions in other rodents, including the Norway rat, Rattus norvegicus. Norway rats express MUPs in urine but information about specific MUP isoform sequences and functions is limited. In this study, we present a detailed molecular characterization of the MUP proteoforms expressed in the urine of two laboratory strains, Wistar Han and Brown Norway, and wild caught animals, using a combination of manual gene annotation, intact protein mass spectrometry and bottom-up mass spectrometry-based proteomic approaches. Detailed sequencing of the urinary MUP isoforms reveals a less complex pattern of primary sequence polymorphism in the rat than the mouse. However, rat MUPs exhibit added complexity in the form of post-translational modifications, including the phosphorylation of Ser4 in some isoforms, and exoproteolytic trimming of specific isoforms.
Project description:The extraocular muscles (EOM) are anatomically and physiologically distinct from other skeletal muscles. EOM are preferentially affected in mitochondrial myopathies, but spared in Duchenne's muscular dystrophy. The anatomical and pathophysiological properties of EOM have been attributed to their unique molecular makeup: an allotype. We used expression profiling to define molecular features of the EOM allotype. We found 346 differentially expressed genes in rat EOM compared with tibialis anterior, based on a twofold difference cutoff. Genes required for efficient, fatigue-resistant, oxidative metabolism were increased in EOM, whereas genes for glycogen metabolism were decreased. EOM also showed increased expression of genes related to structural components of EOM such as vessels, nerves, mitochondria, and neuromuscular junctions. Additionally, genes related to specialized functional roles of EOM such as the embryonic and EOM-specific myosin heavy chains and genes for muscle growth, development, and/or regeneration were increased. The EOM expression profile was validated using biochemical, structural, and molecular methods. Characterization of the EOM expression profile begins to define gene transcription patterns associated with the unique anatomical, metabolic, and pathophysiological properties of EOM.
Project description:Analysis of LBNF1 rat testes from controls, containing both somatic and all germ cell types and from irradiated rats in which all cells germ cells except type A spermatgogonia are eliminated. Results provide insight into distinguishing germ and somatic cell genes and identification of somatic cell genes that are upregulated after irradiation.
Project description:Hepatocellular carcinoma (HCC) initiation is characterized by the sequential stepwise accumulation of molecular alterations. However, the earliest events during the dynamic temporal trend of hepatocarcinogenesis are still unknown. Using a diethylnitrosamine (DEN)-induced rat HCC model, we report a comprehensive transcriptomic landscape of liver tissues at the stages of hepatitis, cirrhosis, and HCC.