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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Liver regeneration provides a unique system for analysis of mitogenesis in intact, fully developed animals. Cellular immediate-early genes likely play an important role in cell cycle regulation and have been extensively studied in mitogen-stimulated fibroblasts lymphocytes but not in liver. We have begun to characterize the immediate-early growth response genes of mitogen-stimulated liver cells, specifically, regenerating liver and insulin-stimulated Reuber H-35 hepatoma cells, and to address differences in growth response between different cell types. Through subtraction and differential screening of cDNA libraries from regenerating liver and insulin-treated H-35 cells, we have extensively characterized 341 differentially expressed clones and identified 52 immediate-early genes. These genes have been partially sequenced and subjected to Northern (RNA) blot analysis, and 41 appear to be novel. Surprisingly, two-thirds of these genes are also expressed in BALB/c 3T3 cells, but only 10 were identified in previous studies of 3T3 cells, and of these, 6 include well-known genes like jun and fos, and only 4 are novel. Approximately one-third of the immediate-early genes identified in mitogen-stimulated liver cells or serum-stimulated NIH 3T3 cells are expressed in a tissue-specific fashion, indicating that cell type-specific regulation of the proliferative response occurs during the immediate-early period. Our findings indicate that the immediate-early response is unusually complex for the first step in a regulatory cascade, suggesting that multiple pathways must be activated. The abundance of immediate-early genes and the highly varied pattern of their expression in different cell types suggest that the tissue specificity of the proliferative response arises from the particular set of these genes expressed in a given tissue.
Mol Cell Biol 1991 Jan
PMID:The immediate-early growth response in regenerating liver and insulin-stimulated H-35 cells: comparison with serum-stimulated 3T3 cells and identification of 41 novel immediate-early genes. 198 33

Liver regeneration after partial hepatectomy was used as an experimental model for studying mammalian cell division and replication. The rate of cell proliferation in this hyperplastic model was correlated with hepatic de novo synthesis of cholesterol, with the hexose monophosphate shunt pathway of glucose metabolism, and with serum lipoproteins. An increase of hepatic cholesterol esters and of incorporation of tritiated water in cholesterol esters was observed at 24 hr after partial hepatectomy. Partial hepatectomy also resulted in an increase of hepatic glucose-6-phosphate dehydrogenase and in alteration of serum lipoproteins, primarily due to a selective decline in high density lipoprotein fraction.
Exp Mol Pathol 1986 Apr
PMID:Hepatic glucose-6-phosphate dehydrogenase, cholesterogenesis, and serum lipoproteins in liver regeneration after partial hepatectomy. 369 35

We examined the interaction of nucleoproteins with thyroid response element (TRE) by south-western method. The proteins that bound specifically to TRE were detected at apparent molecular weight about 30,000 and 15,000 - 10,000. After digestion of nucleoproteins blotted on PVDF membrane with Endoglycosidase H, the amounts of TRE that bound to the nucleoproteins were increased. These results show that carbohydrate moieties of nucleoproteins have an important role on the interaction of the nucleoproteins with TRE. T3 stimulated the binding of TRE to nucleoproteins. The amount of T3 binding to nucleoproteins was changed during liver regeneration. These results indicate that T3 changes the interaction of the nucleoproteins with TRE, so T3 serves as a transducing signal to modulate the gene regulating activity of TRE-binding nucleoproteins. Liver regeneration may be controlled by these modification of interaction of nucleoproteins with DNA.
Biochem Mol Biol Int 1995 Apr
PMID:The interaction between nucleoproteins and thyroid response element (TRE) during regenerating rat liver. 762 37

A possibility of inheritance of androgen and basic genetic programs at the level of unusual estrogen-binding protein (UEBP) by daughter hepatocytes was investigated. Liver regeneration after partial (2/3) hepatectomy or after selective poisoning of hepatocytes of the central zone of hepatic lobules with CCl4 in adult rats were used as models of total and zonal proliferation of hepatocytes, respectively. UEBP content and the pattern of its tissue expression in the course of liver regeneration were monitored by radioligand and immunocytochemical technique. In animals of all groups possessing the androgen program of UEBP expression (intact, castrated and/or hypophysectomized males, and ovariectomized females treated with androgen) UEBP content was shown to be similarly high before initiation and after completion of liver regeneration. Unlike in males, in androgenized females a transient 4-fold increase of UEBP concentration on day 4 after partial hepatectomy was observed. In animals with a basic genetic program at the level of this protein (ovariectomized females, neonatally castrated males) only trace amounts of UEBP were observed in intact as well as in regenerated liver. The data were confirmed by immunocytochemical technique. A gradient mode of distribution of UEBP-contained cells within hepatic lobules with the highest specific staining around central veins was found by immunocytochemical technique in males. Specific staining of centrolobular and periportal hepatocytes was 7- to 10-fold in intact, and 4- to 6-fold in castrated and/or hypophysectomized males. In intact females specific staining was distributed uniformly at extremely low levels similar to that in periportal hepatocytes of males. Androgen administration to ovariectomized females stimulated a significant and stable increase of UEBP content in two layers of hepatocytes surrounding the central vein. Profiles of specific staining of hepatocytes within the hepatic lobules similar to that in control animals were observed after the completion of liver regeneration of different groups of rats. The results obtained suggest all the hepatocytes to be targets for androgen programming, natural in males or experimental in females, while the extent of expression of this program depends on the position of a hepatocyte within the liver lobules and the sex of the animal.
J Steroid Biochem Mol Biol 1993 Feb
PMID:Inheritance of androgen program of male-specific expression of unusual estrogen-binding protein by daughter hepatocytes at rat liver regeneration. 843 19

Liver regeneration is significantly impaired in rats with both alpha-adrenergic hepatic denervation and hereditary vasopressin deficiency. This may implicate a direct role for these agonists in the process of compensatory hyperplasia. The mitogenic capacities of norepinephrine, vasopressin and hepatocyte growth factor (HGF), either alone or in combination were investigated by [3H]thymidine incorporation into hepatocyte cultures prepared from normal and regenerating rat livers. The results show that normal hepatocytes incorporate less [3H]thymidine in response to HGF than do regenerating hepatocytes. In addition, physiological concentrations of vasopressin cause a synergistic stimulation of [3H]thymidine uptake in rat liver cells in the presence of HGF.
J Mol Endocrinol 1997 Apr
PMID:Vasopressin synergistically stimulates DNA synthesis in normal and regenerating rat liver cell cultures in the presence of hepatocyte growth factor. 913 2

Two-thirds partial hepatectomy (PH) induces differentiated cells in the liver remnant to proliferate and regenerate to its original size. The proliferation-specific HNF-3/fork head homolog-11B protein (HFH-11B; also known as Trident and Win) is a family member of the winged helix/fork head transcription factors and in regenerating liver its expression is reactivated prior to hepatocyte entry into DNA replication (S phase). To examine whether HFH-11B regulates hepatocyte proliferation during liver regeneration, we used the -3-kb transthyretin (TTR) promoter to create transgenic mice that displayed ectopic hepatocyte expression of HFH-11B. Liver regeneration studies with the TTR-HFH-11B mice demonstrate that its premature expression resulted in an 8-h acceleration in the onset of hepatocyte DNA replication and mitosis. This liver regeneration phenotype is associated with protracted expression of cyclin D1 and C/EBPbeta, which are involved in stimulating DNA replication and premature expression of M phase promoting cyclin B1 and cdc2. Consistent with the early hepatocyte entry into S phase, regenerating transgenic livers exhibited earlier expression of DNA repair genes (XRCC1, mHR21spA, and mHR23B). Furthermore, in nonregenerating transgenic livers, ectopic HFH-11B expression did not elicit abnormal hepatocyte proliferation, a finding consistent with the retention of the HFH-11B transgene protein in the cytoplasm. We found that nuclear translocation of the HFH-11B transgene protein requires mitogenic signalling induced by PH and that its premature availability in regenerating transgenic liver allowed nuclear translocation to occur 8 h earlier than in wild type.
Mol Cell Biol 1999 Dec
PMID:Premature expression of the winged helix transcription factor HFH-11B in regenerating mouse liver accelerates hepatocyte entry into S phase. 1056 81

Naked DNA transfer of a high-expressing human factor IX (hFIX) plasmid yielded long-term (over 1 1/2 years) and therapeutic-level (0.5-2 microg/ml) gene expression of hFIX from mouse livers. The expression cassette contained a hepatic locus control region from the ApoE gene locus, an alpha1-anti-trypsin promoter, hFIX cDNA, a portion of the hFIX first intron, and a bovine growth hormone polyadenylation signal. In contrast, a hFIX plasmid containing the expression cassette without effective regulatory elements produced initially low-level gene expression that rapidly declined to undetectable levels. Southern analyses of the cellular DNA indicated that the majority of the input genome from either vector persisted as episomal forms of the original plasmids. Together with RT-PCR analyses of the transcripts, these data indicated that at least two processes are critical for sustained gene expression: persistence of vector DNA and transcriptional/posttranscriptional activation. Liver regeneration after partial hepatectomy resulted in a significant decline in transgene expression, further suggestive of decreased episomal plasmid maintenance rather than transgene integration. Transaminase levels and liver histology showed that rapid intravenous plasmid injection into mice induced transient focal acute liver damage (< 5% of hepatocytes), which was rapidly repaired within 3 to 10 days and resulted thereafter in histologically normal tissue. No significant differences were observed between rapid injection of plasmid and saline control solutions. Transient, very low level antibodies directed against hFIX did not prevent the circulation of therapeutic levels of the protein. Gene transfer of hFIX plasmid DNA into liver elicited neither transgene-specific cytotoxic effect nor long-term toxicity. These results demonstrate that long-term expression of hFIX can be achieved by nonviral plasmid transfer and suggest that this occurs independent of integration.
Mol Ther 2001 Jun
PMID:Long-term and therapeutic-level hepatic gene expression of human factor IX after naked plasmid transfer in vivo. 1140 9

In this study, we examined the possibility that impaired proliferation of non-parenchymal cells affects in an impairment of liver regeneration in db/db mice, which are congenitally deficient in receptors for leptin. Liver regeneration after a two thirds partial hepatectomy (2/3 PH) was impaired in 10-week-old female db/db mice. The proliferation of both hepatocytes and non-parenchymal cells estimated from a bromodeoxyuridine (BrdU) labeling index was suppressed, and the protein expression of vascular endothelial growth factor was blocked in db/db mice. Although the extent of fatty change and the level of epidermal growth factor receptor protein expression in the liver were improved in 5-week-old db/db mice, the regeneration of liver was impaired after 2/3 PH in both 5- and 10-week-old db/db mice. These results suggested that suppressed proliferation of non-parenchymal cells contributes to the impairment of liver regeneration in db/db mice. As leptin has also the angiogenic effect, the angiogenic inhibitor FR-118487 was administered to ICR mice to examine liver regeneration after 2/3 PH, and the rate of regeneration was affected. In conclusion, it is suggested that the suppressed proliferation of non-parenchymal cells contributes to the impairment of liver regeneration probably through a disrupted angiogenesis in db/db mice.
Exp Mol Pathol 2005 Aug
PMID:Impaired proliferation of non-parenchymal cells participates in an impairment of liver regeneration in db/db mice. 1600 12

Liver regeneration is a rapid and concerted response to injury, in which growth factor-generated intracellular signals result in activation of transcription factors, DNA synthesis, and hepatocyte proliferation. However, the link between cytoplasmic signals resulting in proliferative response to liver injury remains to be elucidated. We show here that association of Gab1 adaptor protein and Shp2 tyrosine phosphatase is a critical event at the early phase of liver regeneration. Partial hepatectomy (PH) rapidly and transiently induced assembly of a complex comprising Shp2 and tyrosine-phosphorylated Gab1 in wild-type hepatocytes. Consistently, liver-specific Shp2 knockout (LSKO) and liver-specific Gab1 knockout (LGKO) mice displayed very similar phenotypes of defective liver regeneration triggered by PH, including blunted extracellular signal-regulated kinase 1/2 (Erk1/2) activation, decreased expression of immediate-early genes, and reduced levels of cyclins A, E, and B1, as well as suppression of hepatocyte proliferation. In contrast, the Akt and interleukin-6/Stat3 pathways were up-regulated posthepatectomy in LSKO and LGKO mice, accompanied by improved hepatoprotection. Collectively, this study establishes the physiological significance of the Gab1/Shp2 link in promoting mitogenic signaling through the Erk pathway in mammalian liver regeneration.
Mol Cell Biol 2006 Jun
PMID:Concerted functions of Gab1 and Shp2 in liver regeneration and hepatoprotection. 1673 30

Liver regeneration (LR) is a process during which the liver recovers its mass and function after damage due to various causes such as partial hepatectomy (PH). It involves a sequence of well-orchestrated changes in physiological and biochemical activities, especially in the gene expression profile in a variety of liver cells. In order to produce reliable gene expression of target genes in eight kinds of rat hepatic cells during LR, the determination of internal control housekeeping genes (HKGs) is required. Eight kinds of hepatic cells were first isolated from liver tissue with high purity and activity. Then quantitative real-time reverse transcription (RT)-PCR was applied to detect expression changes of six commonly used HKGs (18SrRNA, B2M, ACTB, UBC, GAPDH, and HK1) in eight types of hepatic cells isolated from regenerating liver at 0, 2, 6, 12, 24, 30, 36, 72, 120, and 168 h after PH. The amplification of the HKGs was statistically analyzed by using geNorm algorithm. Using this method, 18SrRNA-UBC, ACTB-HK1, ACTB-GADPH, B2M-ACTB, 18SrRNA-UBC, B2M-UBC, B2M-ACTB, and B2M-UBC were found to be the two most stable reference genes for rat regenerating hepatocytes, hepatic stellate cells, Kupffer cells, biliary epithelial cells, sinusoidal endothelial cells, pit cells, dendritic cells, and oval cells, respectively, regardless of the stages of LR. In conclusion, this study has laid a good foundation for investigating gene expression of target genes in different types of hepatic cells during LR.
Mol Biotechnol 2010 Sep
PMID:Reference gene selection for real-time RT-PCR in eight kinds of rat regenerating hepatic cells. 2033 55


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