ABSTRACT: Expression of rat hepatocytic progenitor cells with and without hepatic Thy1-positive cells in retrorsine/partial hepatectomy treated rats models.
Project description:Small hepatocyte-like progenitor cells (SHPCs) are hepatocytic progenitor cells that transiently form clusters in rat livers treated with retrorsine and with 70% partial hepatectomy (PH). We previously reported that transplantation of Thy1+ cells derived from D-galactosamine-treated livers promotes SHPC expansion, resulting in the acceleration of liver regeneration. Extracellular vesicles (EVs) produced by Thy1+ cells act on sinusoidal endothelial cells (SECs) and Kupffer cells to secrete IL17B and IL25, respectively, resulting in SHPC activation through IL17 receptor B (RB) signaling. Our aim is to identify factors in Thy1-EVs that activate IL17RB signaling. Thy1+ cells isolated from rats with D-galactosamine-induced liver injury were cultured for one week. Although some liver stem/progenitor cells proliferated into colonies, others maintained as mesenchymal cells (MCs). Thy1-MCs or Thy1-liver stem/progenitor cells were transplanted into retrorsine/PHtreated livers to examine their effects on SHPCs. SHs isolated from adult rat livers were used to validate factors regulating growth induction. The number and size of SHPCs remarkably increased in livers transplanted with Thy1-MCs. Comprehensive analysis of Thy1-MC-EVs revealed that miR-199a-5p, CINC-2, and MCP-1 are candidates for stimulating SHPC growth. Administration of the miR-199a-5p mimic, and not CINC-2, promoted SH growth. SECs treated with CINC-2 induced IL17b expression and their conditioned medium promoted SH growth. Thy1-MC transplantation may accelerate liver regeneration due to SHPCs expansion, which is stimulated by CINC-2/IL17RB signaling and miR-199a-5p.
Project description:We previously identified the mTOR pathway as critical to progenitor cell proliferation in a model of liver injury, we investigated the temporal activation of mTOR signaling in a rat model of hepatic carcinogenesis. The model employed chemical carcinogens and partial hepatectomy to induce progenitor marker-positive HCC. Rats were administered the mTOR inhibitor rapamycin for a three week period and liver harvested one month following cessation of rapamycin treatment. Short-term rapamycin treatment resulted in a significant reduction of focal lesion burden. Microarray analysis was performed to characterize the gene expression signature of persistent focal lesions in the rapamcyin and placebo treated animals. This analysis revealed a persistent effect of short-term mTORC1 inhibition on gene expression that resulted in a genetic signature reminiscent of normal liver.
Project description:This SuperSeries is composed of the following subset Series: GSE20425: Hepatic gene expression during liver regeneration in response to partial hepatectomy: early time points (0.5h,1h,2h,4h) GSE20426: Hepatic gene expression during liver regeneration in response to partial hepatectomy: late time points (24h, 38h, 48h) Refer to individual Series
Project description:Evaluation of early transcriptional changes in blood brain barrier genes involved in the patogenesis of brain edema associated with ALF. Two different well stablished rat models were analyzed: Portacaval anastomosis plus hepatic artery ligation and portacaval anastomosis plus total hepatectomy. ALF was induced by portocaval anastomosis (PCA) and 24 hours after the surgery animals underwent hepatic artery ligation (HAL) or total hepatectomy (HEP). Sham rats were subjected to a fictitious two-step surgery. Between 8 and 12 hours after the last surgery rats were euthanized by decapitation, to avoid anesthetic effects, and cortical microvessels isolated.
Project description:Purpose: The goal of this study was to determine biological consequences during liver regeneration following partial hepatectomy in mice by next-generation sequencing. A particular interest was to compare mice with either a floxed b-PDGFR allele to mice that harbored a deletion of b-PDGFR in hepatic stellate cells (HSCs), by crossing b-PDGFR fl/fl mice with transgenic GFAP-Cre mice. Methods: b-PDGFR fl/fl mice or mice with a HSC-specific deletion of b-PDGFR underwent either sham operation or 70% partial hepatectomy. Following 72 hours, livers were collected and total RNA was extracted using tizol, followed by a purification using Quiagen spin columns including an on-column DNAse digestion step. Conclusion: Our study represents a detailed analysis of hepatic transcriptome, with biologic replicates, generated by RNA-seq technology of livers following sham operation or partial hepatectomy in b-PDGFR fl/fl mice or b-PDGFRfl/fl/GRAP-Cre mice. Whole liver mRNA profiles of sham operated livers or livers collected 72hours after partial hepatectomy of beta-PDGFR fl/fl and beta-PDGFR fl/fl/GFAP-Cre (creating a hepatic stellate cell-specific deletion of b-PDGFR) mice were generated by deep sequencing, in duplicate, using Illumina HiSeq2000.
Project description:4 Adult male Sprague-Dawley rats (275-350 g) were anesthetized and subjected to hepatectomy sham surgery (abdominal cavity was opened, liver was handled, but no tissue resection was made). 1 hour after the surgery rats were killed and liver samples were harvested. This study was conducted to analyzes the effects of surgical stress on gene expression levels in rat liver. It provides additional data to 1-6 h partial hepatectomy study (Series GSE7415). Keywords: 1h hepatectomy sham surgery
Project description:Our strategy was to manipulate mTOR signaling in vivo, then characterize the transcriptome and translating mRNA in liver tissue. In adult rats, we used the non-proliferative growth model of refeeding after a period of fasting, and the proliferative model of liver regeneration following partial hepatectomy. We also studied livers from pre-term fetal rats (embryonic day 19-20) in which fetal hepatocytes are asynchronously proliferating. All three models employed rapamycin to inhibit mTOR signaling.
Project description:Purpose: The goal of this study was to determine biological consequences during liver regeneration following partial hepatectomy in mice by next-generation sequencing. A particular interest was to compare mice with either a floxed b-PDGFR allele to mice that harbored a deletion of b-PDGFR in hepatic stellate cells (HSCs), by crossing b-PDGFR fl/fl mice with transgenic GFAP-Cre mice. Methods: b-PDGFR fl/fl mice or mice with a HSC-specific deletion of b-PDGFR underwent either sham operation or 70% partial hepatectomy. Following 72 hours, livers were collected and total RNA was extracted using tizol, followed by a purification using Quiagen spin columns including an on-column DNAse digestion step. Conclusion: Our study represents a detailed analysis of hepatic transcriptome, with biologic replicates, generated by RNA-seq technology of livers following sham operation or partial hepatectomy in b-PDGFR fl/fl mice or b-PDGFRfl/fl/GRAP-Cre mice.
Project description:We investigated by microarray analysis the expression pattern of hepatic genes in young and old untreated mice and the differences in gene expression profile following surgical partial hepatectomy (2/3 PH).