Project description:Silicosis, a fibrotic granulomatous lung disease, may occur through accidental high-dose or occupational inhalation of silica, leading to acute/accelerated and chronic silicosis, respectively. While chronic silicosis has a long asymptomatic latency, lung inflammation and apoptosis are hallmarks of acute silicosis. In animal models, histiocytic granulomas develop within days after high-dose intratracheal silica instillation. However, following chronic inhalation of occupationally relevant doses of silica, discrete granulomas resembling human silicosis arise months after the final exposure without significant lung inflammation/apoptosis. To identify molecular events associated with chronic silicosis, lung RNAs from controls or chronically silica-exposed rats were analyzed by Affymetrix at 28 wk after silica exposures. Results suggested a significant upregulation of 144 genes and downregulation of seven genes. The upregulated genes included complement cascade, chemokines/chemokine receptors, G-protein signaling components, metalloproteases, and genes associated with oxidative stress. To examine the kinetics of gene expression relevant to silicosis, qPCR, ELISA, Luminex-bead assays, Western blotting, and/or zymography were performed on lung tissues from 4 d, 28 wk, and intermediate times after chronic silica exposure and compared with 14 d acute silicosis samples. Results indicated that genes regulating fibrosis (secreted phosphoprotein-1, CCL2, and CCL7), redox enzymes (superoxide dismutase-2 and arginase-1), and the enzymatic activities of matrix metalloproteinases 2 and 9 were upregulated in acute and chronic silicosis; however, proinflammatory cytokines were strongly upregulated only in acute silicosis. Thus, inflammatory cytokines are associated with acute but not chronic silicosis; however, genes regulating fibrosis, oxidative stress, and metalloproteases may contribute to both acute and chronic silicosis. 3 rats were chronically exposed to silica by inhalation. Briefly, exposure chambers were maintained with an airflow rate of ~15 cfm and temperature range of 22‚Äì26¬?C. Animals were exposed to 6.2 mg/m3 aerosolized silica (Min-U-Sil 5; U.S. Silica, Mill Creek, OK) with an average particle size of 1.75 ¬± 0.05 mm (mass median aerodynamic diameter) 6 h/d, 5 d/wk (Monday‚ÄìFriday) for 6 wk. 3 control animals received filtered air under similar inhalation conditions.
Project description:Silicosis, a fibrotic granulomatous lung disease, may occur through accidental high-dose or occupational inhalation of silica, leading to acute/accelerated and chronic silicosis, respectively. While chronic silicosis has a long asymptomatic latency, lung inflammation and apoptosis are hallmarks of acute silicosis. In animal models, histiocytic granulomas develop within days after high-dose intratracheal silica instillation. However, following chronic inhalation of occupationally relevant doses of silica, discrete granulomas resembling human silicosis arise months after the final exposure without significant lung inflammation/apoptosis. To identify molecular events associated with chronic silicosis, lung RNAs from controls or chronically silica-exposed rats were analyzed by Affymetrix at 28 wk after silica exposures. Results suggested a significant upregulation of 144 genes and downregulation of seven genes. The upregulated genes included complement cascade, chemokines/chemokine receptors, G-protein signaling components, metalloproteases, and genes associated with oxidative stress. To examine the kinetics of gene expression relevant to silicosis, qPCR, ELISA, Luminex-bead assays, Western blotting, and/or zymography were performed on lung tissues from 4 d, 28 wk, and intermediate times after chronic silica exposure and compared with 14 d acute silicosis samples. Results indicated that genes regulating fibrosis (secreted phosphoprotein-1, CCL2, and CCL7), redox enzymes (superoxide dismutase-2 and arginase-1), and the enzymatic activities of matrix metalloproteinases 2 and 9 were upregulated in acute and chronic silicosis; however, proinflammatory cytokines were strongly upregulated only in acute silicosis. Thus, inflammatory cytokines are associated with acute but not chronic silicosis; however, genes regulating fibrosis, oxidative stress, and metalloproteases may contribute to both acute and chronic silicosis.
Project description:Acute rejection episodes trigger chronic renal allograft vasculopathy. Numerous leukocytes, predominantly monocytes, accumulate in graft blood vessels during reversible acute rejection preceding chronic rejection of rat kidneys. We speculate that they contribute to transplant vasculopathy and set out to characterize them. Allogeneic renal transplantation was performed in the Fischer 344 to Lewis rat strain combination, Lewis isografts served as controls. Leukocytes were harvested by intensive perfusion of graft blood vessels and subjected to flow cytometry, quantitative RT-PCR and genome-wide transcriptional profiling.
Project description:Global mRNA expression profiling of transplanted rat hindlimbs (muscle and skin) were collected using Agilent rat whole genome array (Agilent-028282 Whole Rat Genome Microarray 4x44K v3). Hind limb transplantation between Fischer344 (donor) and Lewis (recipient) rats were performed. Isogenic transplantations served as controls. Administration of irregular immunosuppression induced chronic rejection. At the endpoint (post-operativ day 100), hind limbs presented clinicial, histomorphological and genetic changes, known to be highly suspicious for chronic rejection.
Project description:Acute rejection episodes trigger chronic renal allograft vasculopathy. Numerous leukocytes, predominantly monocytes, accumulate in graft blood vessels during reversible acute rejection preceding chronic rejection of rat kidneys. We speculate that they contribute to transplant vasculopathy and set out to characterize them. Allogeneic renal transplantation was performed in the Fischer 344 to Lewis rat strain combination, Lewis isografts served as controls. Leukocytes were harvested by intensive perfusion of graft blood vessels and subjected to flow cytometry, quantitative RT-PCR and genome-wide transcriptional profiling. Kidneys of LEW and F344 rats were transplanted in LEW rats. Five biological replicates were performed for both isogenic and allogenic transplantation. Transcriptomes of allogenics were compared to isogenics on 5 dual-color hybridizations.
Project description:Gene expression profiles in hearts of Lewis rats immunized with a peptide of human alpha1A-adrenergic receptor. The pathophysiological relevance of chronic autoantibodies against alpha-1A-adrenergic receptor stimulation in rats was investigated. Lewis rats were immunized using synthesized peptides of second extracellular loop of the human alpha-1A-adrenergic receptor and raised for one year. The gene expression in hearts of three immunized and three control rats were analyzed using Affymetrix Rat Genome 230 2.0 Arrays.
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.