Peroxisome proliferation is a cellular response to many chemical compounds affects including natural and modified fatty acids, phthalate and adipate ester plasticizers, leukotriene antagonists, acetylsalicylic acid and certain pathophysiological conditions including dramatic change of cellular morphology and enzymatic activity. Peroxisome proliferation phenomenon is seen primarily in liver and kidney. Hormones and nutritional factor can regulate peroxisome proliferation response. Sustained peroxisome proliferation can lead to hepatocarcinogenesis. The three types of peroxisome proliferator activated receptor, termed PPAR alpha, PPAR beta, and PPAR gamma, expressed in specific tissue, are consisted of a specific a nuclear receptor superfamily. After more than 10 years world wide research, the function of PPAR is clarified, as PPAR gamma, the master of thrifty genes, controls the expression of genes relative to adipogenesis, diabetes mellitus and obesity. The receptor is involved in transcriptional control of numerous cellular processes including cell cycle control, inflammation, immunoregulation and carcinogenesis.
Adipocytes ; cytology ; Animals ; Cell Differentiation ; Energy Metabolism ; genetics ; Humans ; Intracellular Signaling Peptides and Proteins ; Nuclear Receptor Coactivators ; Peroxisome Proliferators ; Receptors, Cytoplasmic and Nuclear ; genetics ; physiology ; Transcription Factors ; genetics ; physiology

Abstract:By using PVX derived vector pGR107, the effect of BYDV-MP nuclear localization signal on the movement of PVX was studied. BYDV-MP was cloned into pGR107 using GFP as an indicator. BYDV-MP was then shown to induce the systemic infection and exacerbate the symptom of PVX through infecting Nicotiana benthamiana. When the PVX gene encoding 25kD protein, which functioned as a systematic movemnet protein,was deleted and the above experiment was repeated, the result showed that BYDV-MP could compensate the systemic movement of PVX. A serial mutants with substitutions on the fifth, sixth and seventh amino acids of BYDV-MP nuclear localization signal was further constructed. It was found that the mutants at the fifth, sixth amino acids in BYDV-MP nuclear localization signal could only delay or weaken systemic movement of PVX whereas the mutant at seventh amino acid could entirely inhibit systemic movement of PVX.
Amino Acid Sequence ; Green Fluorescent Proteins ; genetics ; Luteovirus ; physiology ; Molecular Sequence Data ; Nuclear Localization Signals ; chemistry ; physiology ; Plant Viral Movement Proteins ; physiology ; Potexvirus ; genetics ; physiology

Gene transfer technology is being used to enhance agronomic performance or improve quality traits in a wide variety of crop species. However, it is sometimes severely handicapped by difficulty in obtaining material in which transgene expression is predictable and stable over many generations. Because integration seemed to occur randomly in the plant genome, it was thought that some transgenes would be integrated in a relatively uncondensed, transcriptionally active chromatin environment, while others in a condensed, transcriptionally inert chromatin structure. Nuclear matrix attachment regions (MARs) are defined as DNA sequences that bind preferentially to the proteins of the nuclear matrix. They typically are localized at the borders of gene domains, implicating them in the formation of individual loops of higher order chromatin structure and transcription regulation. When MARs are positioned on either side of a transgene their presence usually results in higher and more stable espression in transgenic plants, most likely by minimizing gene silencing. In this review, we focus mainly on novel findings and our observations concerning the function of MARs in transcription regulation. Our objective is not only to summarize the current data and present several possible models to explain MAR effects on the transcription regulation, but also to point out some open questions involving the utilization of MARs in constructing high efficient expression vectors.
Chromatin ; physiology ; DNA ; metabolism ; Gene Expression Regulation, Plant ; Models, Genetic ; Nuclear Matrix ; metabolism ; Nuclear Proteins ; metabolism ; Transcription, Genetic ; Transgenes ; genetics

Self-renewal of hematopoietic stem cells is vital for the sustained daily production of blood cells. The Bmi-1 gene is a putative oncogene belonging to the Polycomb group family. Recent studies have shown that the Polycomb-group gene Bmi-1 is indispensable for regulation of self-renewal of normal and leukemic stem cells. The research progress on structure and function of Bmi-1 gene, and its role in self-renewal of hematopoietic stem cells was reviewed.
Cell Differentiation ; physiology ; Cell Division ; physiology ; Hematopoietic Stem Cells ; cytology ; physiology ; Humans ; Nuclear Proteins ; genetics ; physiology ; Polycomb Repressive Complex 1 ; Proto-Oncogene Proteins ; genetics ; physiology ; Repressor Proteins ; genetics ; physiology

AIMTo investigate the roles of liver X receptors (LXR) in the lipid composition and gene expression regulation in the murine caput epididymidis. LXR are nuclear receptors for oxysterols, molecules derived from cholesterol metabolism that are present in mammals as two isoforms: LXRalpha, which is more specifically expressed in lipid-metabolising tissues, such as liver, adipose and steroidogenic tissues, and macrophages, whereas LXRbeta is ubiquitous. Their importance in reproductive physiology has been sustained by the fact that male mice in which the function of both LXR has been disrupted have fertility disturbances starting at the age of 5 months, leading to complete sterility by the age of 9 months. These defects are associated with epididymal epithelial degeneration in caput segments one and two, and with a sperm midpiece fragility, leading to the presence of isolated sperm heads and flagella when luminal contents are recovered from the cauda epididymidis.

METHODSThe lipid composition of the caput epididymidis of wild-type and LXR-deficient mice was assessed using oil red O staining on tissue cryosections and lipid extraction followed by high performance liquid chromatography or gas chromatography. Gene expression was checked by quantitative real time polymerase chain reaction.

RESULTSUsing LXR-deficient mice, we showed an alteration of the lipid composition of the caput epididymidis as well as a significantly decreased expression of the genes encoding SREBP1c, SCD1 and SCD2, involved in fatty acid metabolism.

CONCLUSIONAltogether, these results show that LXR are important regulators of epididymal function, and play a critical role in the lipid maturation processes occurring during sperm epididymal maturation.

Animals ; DNA Primers ; DNA-Binding Proteins ; deficiency ; genetics ; physiology ; Epididymis ; cytology ; physiology ; Epithelial Cells ; physiology ; Fatty Acids ; metabolism ; Homeostasis ; Lipids ; physiology ; Liver X Receptors ; Male ; Mice ; Mice, Knockout ; Orphan Nuclear Receptors ; Polymerase Chain Reaction ; Receptors, Cytoplasmic and Nuclear ; deficiency ; genetics ; physiology

Enterovirus 71 (EV71) is a neurotropic pathogen that can induce hand, foot and mouth disease in children. There is an appreciable mortality rate after EV71 infections. The mechanism of action of EV71 replication is not known. Recent work has identified some of cell factors of the host that participate in the synthesis of the RNA and proteins of EV71 (e.g., hnRNP K, reticulon 3 (RTN 3)). In that work, researchers used a competitive assay to show that hnRNP K can interact with EV71 5' UTR, which is required for efficient synthesis of viral RNA. Using a yeast two-hybrid system, other researchers demonstrated that RTN 3 interacts with the N-terminal domain of EV71 2C, which is crucial for replication of viral RNA. Here, we discuss recent work focusing on the molecular mechanisms of hnRNP K and RTN 3 in the synthesis of the RNA and proteins of EV71.
Animals ; Carrier Proteins ; genetics ; metabolism ; Enterovirus A, Human ; genetics ; physiology ; Enterovirus Infections ; genetics ; metabolism ; virology ; Heterogeneous-Nuclear Ribonucleoprotein K ; Host-Pathogen Interactions ; Humans ; Membrane Proteins ; genetics ; metabolism ; Nerve Tissue Proteins ; genetics ; metabolism ; Ribonucleoproteins ; genetics ; metabolism ; Viral Proteins ; genetics ; metabolism ; Virus Replication

Animals ; Apoptosis ; Cell Cycle ; Cell Cycle Proteins ; genetics ; metabolism ; physiology ; DNA Repair ; Homeodomain Proteins ; genetics ; metabolism ; physiology ; Humans ; Inhibitor of Growth Protein 1 ; Intracellular Signaling Peptides and Proteins ; genetics ; metabolism ; physiology ; Neoplasm Metastasis ; Neoplasms ; metabolism ; pathology ; Neovascularization, Pathologic ; pathology ; Nuclear Proteins ; genetics ; metabolism ; physiology ; Prognosis ; Receptors, Cytoplasmic and Nuclear ; genetics ; metabolism ; physiology ; Signal Transduction ; Transcription Factors ; genetics ; metabolism ; physiology ; Tumor Suppressor Protein p53 ; metabolism ; Tumor Suppressor Proteins ; chemistry ; genetics ; metabolism ; physiology

OBJECTIVETo investigate the effect of trans-acting factor(s) on rat glutathione S-transferase P1 gene (rGSTP1) transcription regulation in tumor cells.

METHODSThe binding of trans-acting factor(s) to two enhancers of the rGSTP1 gene, glutathione S-transferase P enhancer I (GPEI) and glutathione S-transferase P enhancer II-1 (GPE II-1), was identified by an electrophoretic mobility shift assay (EMSA). The molecular weight of trans-acting factor was measured in a UV cross-linking experiment.

RESULTSTrans-acting factor interacting with the core sequence of GPEI (cGPEI) were found in human cervical adenocarcinoma cell line (HeLa) and rat hepatoma cell line (CBRH7919). These proteins were not expressed in normal rat liver. Although specific binding proteins that bound to GPE II-1 were detected in all three cell types, a 64 kDa binding protein that exists in HeLa and CBRH7919 cells was absent in normal rat liver.

CONCLUSIONcGPEI, GPEII specific binding proteins expressed in HeLa and CBRH7919 cells may play an important role in the high transcriptional level of the rGSTP1 gene in tumor cells.

Animals ; Carrier Proteins ; metabolism ; Enhancer Elements, Genetic ; physiology ; Gene Expression Regulation, Enzymologic ; Glutathione S-Transferase pi ; Glutathione Transferase ; genetics ; Isoenzymes ; genetics ; Nuclear Proteins ; metabolism ; Rats ; Transcription, Genetic

BACKGROUNDNucleostemin is essential for the proliferation and survival of stem and cancer cells, but it is unknown whether this newly identified molecule is involved in prostate cancer pathogenesis.

METHODSTotal RNA and protein were extracted from prostate cancer tissues and PC-3, LNCap and DU145 cell lines. The nucleostemin mRNA and protein expression were measured by RT-PCR and Western blot. Immunohistochemistry was also used to detect the nucleostemin protein expression in prostate cancer tissues and PC-3 cells. A nucleostemin specific, short hairpin RNA, expression plasmid was used to transfect PC-3 cells. The changes of nucleostemin gene were detected and the proliferative capacity of the cells was determined.

RESULTSNucleostemin was highly expressed in prostate cancer tissues and cell lines. Nucleostemin expression level in the silencer group PC-3 cells remarkably reduced. The proliferation rate of silencer group PC-3 cells decreased and the percentage of G1 stage cells increased. The neoplasm forming capacity in nude mice of the silencer group PC-3 cells decreased significantly.

CONCLUSIONSNucleostemin is highly expressed in prostate cancer tissues and cell lines. The proliferative capacity of PC-3 cells is remarkably reduced after silencing nucleostemin gene expression.

Animals ; Apoptosis ; Carrier Proteins ; analysis ; genetics ; physiology ; Cell Cycle ; Cell Line, Tumor ; Cell Proliferation ; GTP-Binding Proteins ; Humans ; Male ; Mice ; Nuclear Proteins ; analysis ; genetics ; physiology ; Prostatic Neoplasms ; genetics ; pathology ; RNA, Messenger ; analysis

To better understand the relationship between specific chromosome changes found in human lung tumors and their phenotypic consequences a the tissue level, an in situ hybridization (ISH) procedure of chromosome 17 and immunohistochemistry of proliferating cell nuclear antigen (PCNA) were done. The deparaffinized sections were stained with pericentromeric probes for chromosome 17 and an immunohistochemical study of a monoclonal antibody against PCNA were performed. The numbers of chromosome signals were than compared with the positivity of PCNA expression. The mean numbers of chromosome were 1.62 in normal lymphocytes and 2.48 in lung cancer cells. Tumors showed a high mean positivity of PCNA of 43.4%. Mean PCNA expression was higher in squamous carcinomas than in adenocarcinomas (p<0.05). A linear correlation between numbers of ISH signals and PCNA expression was not demonstrated, but there was a tendency of increasing PCNA positivity according to increasing numbers of ISH signals in adenocarcinomas of the lung and the tumor tissues which were over 50% positive PCNA expression. There was no linear correlation between numbers of ISH signals, PCNA positivity and tumor stages, and keratinization of squamous cell lung cancer. These results suggest that ISH will prove to bo an important tool for determining the underlying genetic basis for tissue phenotypic heterogeneity by allowing genetic determinations to be made on paraffin-embedded tissue sections where histologic architecture is preserved, and immunohistochemical nuclear staining with anti-PCNA on routinely processed tissue is a simple technique for the assessment of proliferation in non-small cell lung carcinoma.
Antigens, Neoplasm/analysis ; Cell Differentiation/physiology ; Cell Division/physiology ; Chromosome Aberrations/*physiology ; *Chromosomes, Human, Pair 17 ; Humans ; Immunohistochemistry ; In Situ Hybridization ; Lung Neoplasms/*genetics/pathology ; Neoplasm Staging ; Nuclear Proteins/analysis ; Phenotype ; Proliferating Cell Nuclear Antigen