Project description:Global miRNA expression was examined in liver tissues from male and female F344 rats over the life span for the purpose of evaluating their possible roles in susceptibility to liver toxicity and disease. Hepatic miRNA expression was characterized at 2, 5, 6, 8, 15, 21, 52, 78, and 104 weeks of age in both sexes using Agilent 8x15k rat miRNA microarrays containing multiple probes for 677 unique miRNAs. Data processing, 75% normalization, and statistical analysis of microarray data were performed in SAS. Functional analysis (Ingenuity) was performed on select miRNAs exhibiting prominent age and sex expression differences. +
Project description:A series of two color gene expression profiles obtained using Agilent 44K expression microarrays was used to examine sex-dependent and growth hormone-dependent differences in gene expression in rat liver. This series is comprised of pools of RNA prepared from untreated male and female rat liver, hypophysectomized (‘Hypox’) male and female rat liver, and from livers of Hypox male rats treated with either a single injection of growth hormone and then killed 30, 60, or 90 min later, or from livers of Hypox male rats treated with two growth hormone injections spaced 3 or 4 hr apart and killed 30 min after the second injection. The pools were paired to generate the following 6 direct microarray comparisons: 1) untreated male liver vs. untreated female liver; 2) Hypox male liver vs. untreated male liver; 3) Hypox female liver vs. untreated female liver; 4) Hypox male liver vs. Hypox female liver; 5) Hypox male liver + 1 growth hormone injection vs. Hypox male liver; and 6) Hypox male liver + 2 growth hormone injections vs. Hypox male liver. A comparison of untreated male liver and untreated female liver liver gene expression profiles showed that of the genes that showed significant expression differences in at least one of the 6 data sets, 25% were sex-specific. Moreover, sex specificity was lost for 88% of the male-specific genes and 94% of the female-specific genes following hypophysectomy. 25-31% of the sex-specific genes whose expression is altered by hypophysectomy responded to short-term growth hormone treatment in hypox male liver. 18-19% of the sex-specific genes whose expression decreased following hypophysectomy were up-regulated after either one or two growth hormone injections. Finally, growth hormone suppressed 24-36% of the sex-specific genes whose expression was up-regulated following hypophysectomy, indicating that growth hormone acts via both positive and negative regulatory mechanisms to establish and maintain the sex specificity of liver gene expression. For full details, see V. Wauthier and D.J. Waxman, Molecular Endocrinology (2008)
Project description:Knee osteoarthritis (KOA), as a degenerative multifactorial disease, affects the quality of life and mental health of patients, and also brings a huge socioeconomic burden. Treating synovitis have shown promise as anti-inflammatory therapeutics in mitigating OA symptoms and disease progression. Here, by analysing synovial single-cell sequencing (scRNA-seq) data from KOA, we found that synovial fibroblasts (FLS) in OA synovium showed a distinct pro-inflammatory phenotype. We collected synovial tissue from patients with clinical OA as well as from healthy donors, and histological examination was consistent with findings in scRNA-seq. Inspired by recent cross-tissue fibroblast lineage studies, we identified by sequencing that healthy FLS in synovial tissues share transcriptome-level similarities with dermal fibroblasts (DFb). Subsequently, we revealed the local as well as systemic distribution of intra-articular injected DFbs by constructing/extracting two types of rat fibroblasts (luciferase DFbs as well as GFP DFbs). The results demonstrate that DFbs can be locally retained in the synovium for up to three weeks following targeted engrafting on it. And intra-articular injection does not result in DFbs migration to vital organs or the occurrence of histological changes in these organs. A rat model of KOA was constructed by anterior cruciate ligament transection (ACLT) in order to study the therapeutic effect of DFbs on KOA. After injection, the rats showed improvement in painful gait. In addition, histological as well as imaging results showed reduced synovitis and improvement in articular cartilage. Finally we verified the protective effect of DFbs on cytokine-stimulated chondrocytes in a co-culture system.
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.