To explore the effects of FK506 on the inhibition by triptolide (TP) of cell proliferation and expressions of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and their inducing products PGE2, NO in human rheumatoid arthritis synovial fibroblasts (RASF), and to study the mechanisms of combination of FK506 and TP in RA therapy, RASF used in the experiments were obtained from synovial tissue of patients with RA and were cultured. RASF were pretreated with FK506(10-1000 nmol/L)for 2 h, then the cells were stimulated with TNF alpha(20 microg/L) in the presence or absence of TP (10 microg/L). The RASF proliferation was determined by [(3)H]-TdR incorporation, and the productions of PGE2 and NO in culture supernatants of RASF were detected with competitive ELISA and enzyme reduction of nitrate. Expression of COX-2 and iNOS mRNA in RASF were analyzed by semi quantitative RT-PCR. Expressions of COX-2 and iNOS protein were estimated by Western blot method and cellular enzyme immunoassay in synovial fibroblasts. NF-kappa B activity in whole-cell extract of RASF was also measured by an ELISA-based method. Results showed that neither FK506 nor TP at lower concentration (10 microg/L) alone affected TNF alpha-induced COX-2, iNOS expression and production of PGE2, NO in synovial cells. Combined treatment of FK506 and a lower concentration of TP (10 microg/L) down-regulated COX-2 and iNOS mRNA and protein expression, and their inducing products PGE2 and NO of synovial fibroblasts. This effect was positively correlated with FK506 concentrations (10-1000 nmol/L). NF-kappa B activity in TNF alpha-stimulated synovial cells was suppressed more profoundly by FK506 plus TP (10 microg/L) treatment than those with TP (10 microg/L) alone. No change was observed in inhibition of proliferation of synovial cells after combined treatment of FK506 and TP. In conclusion, FK506 enhanced TP-mediated down-regulation of COX-2, iNOS and their inducing products PGE2, NO in human RASF by suppressing the activity of NF-kappa B.

This study was designed to investigate the impact of selenium dioxide (SeO2) on regulatory regions P250 of c-fos gene and to seek possible regulation mechanism.

To investigate the effects of Aining on the genes of the human gastric cancer cells.

The aim of this study was to investigate the protective effect of adenosine (ADO) on cardiomyocytes following hypoxia/reoxygenation (H/R) and its molecular mechanism. Primary cultured cardiomyocytes of neonatal rats were divided into two groups, namely H/R (control) and ADO (1.0 micromol/L) groups. The morphologic changes in cardiomyocytes were observed under an inverted phase-contrast microscope. The following parameters of the two groups were determined: lactate dehydrogenase (LDH) activity, intracellular calcium concentration and malondialdehyde (MDA) content. Tumor necrotic factor (TNF-alpha) assay was performed using an ELISA kit and NF-kappaB in the nucleus was analyzed by electrophoretic mobility shift assay (EMSA). The results are as follows: (1) after H/R injury, cardiomyocytes contracted, tending to get round in shape and its pseudopods decreased, while marked morphological changes were not observed in ADO group; (2) LDH leakage maintained at a lower level in ADO group than that in the control group during H/R (both P<0.01); (3) ADO significantly reduced the concentration of calcium in cells and prevented calcium overload during H/R (both P<0.01); (4) ADO markedly reduced the content of MDA during H/R (both P<0.01); (5) ADO inhibited the production of TNF-alpha during H/R (both P<0.01); and (6) ADO down-regulated NF-kappaB binding activity of cardiomyocytes during H/R (both P<0.01) The results suggest that (1) exogenous ADO attenuates H/R injury of cultured cardiomyocytes; (2) exogenous ADO inhibits the production of TNF-alpha after H/R injury; (3) exogenous ADO prevents the activation of NF-kappaB, which may be the molecular mechanism of down-regulation of TNF-alpha expression.

The nifA gene of Azospirillum brasilense Yu62 was cloned and sequenced. The expression of nifA gene was investigated in wild type strain Azospirillum brasilense Yu62. The results show that expression of nifA gene is not repressed by ammounium and oxygen completely. But the expression of Yu62 nifA gene is different from that of strain Sp7 nifA gene. Expression of Yu62 nifA seems more sensitive to oxygen than that of Sp7 nifA which shows the highest expression in condition of aerobic, while the Yu62 nifA gene shows the highest expression in the condition of microaerobic. The regulation of NifA protein activity by ammonia and oxygen was investigated. Results showed that the NifA protein is repressed by ammonia, 1 mmol/L NH4Cl can inhibit activity of NifA protein completely. Oxygen concentration affects activity of NifA protein. NifA protein is highly active in 0.4%-0.5% O2.

The large plasmids of strain 7653R were digested with restriction enzyme EcoRI. Their DNA fragments were cloned into the expression vector pMP220 to construct a lacZ fusion pool, which were transferred into the recipient strain 7653R. Tri-transconjugants were selected onto plates containing X-gal and seed extract. Five blue colonies were assayed of their beta-galactosidase activity after incubation with or without seed extract. A positive induced strain HN18 was obtained. Hybridization of nodDABC probe on the recombinant plasmid pHN18 showed a 1.7 kb positive band. The evidence makes a deduction that the pHN18 contains a promoter of nod operon.

S-Adenosyl-L-methionine(SAM) is an important metabolic intermediate in the metabolic flux of sulphur. SAM is involved in three key metabolic pathways: transmethylation, transsulfuration and polyamine synthesis. As a potential therapeutic agent, SAM is being used as over the counter drug and nutrient supplement. An expression vector, harboring SAM synthetase 2 gene from S. cerevisiae and regulated by the glyceraldehyde-3-phosphate dehydrogenase gene promoter P(GAP), was transformed into GS115 strain of P. pastoris. Through zeocin resistance and expression screening, a recombinant strain was obtained that had high SAM yield and the fermentation conditions were optimized. The results showed that carbon source, nitrogen source, pH and dissolved oxygen had significant effects on the accumulation of SAM. The SAM production of the recombinant cells reached 2.49 g/L after fermentation for three days under the optimized conditions. The present studies show that fermentation of recombinant P. pastoris strain, expressing heterologous SAM synthetase gene, may be a promising approach for the production of SAM.

Sodium butyrate, a histone deacetylase inhibitor, can inhibit tumor conditioned medium-induced levels of promoter II and I. 3-specific transcripts. This study was designed to investigate the action of sodium butyrate on promoter II and I. 3 activity, which can be directed to elucidation of local estrogen production in breast cancer.

To examine the binding sites of miyabenol C (Miy C) and kobophenol A ( Kob A) with estrogen receptor (ER), computer modeling was applied to determine 3D structure of Miy C and Kob A. Molecular docking of the components to ER was carried out to find the binding sites between them. PCR mutagenesis was used to change the structure of ER cDNA. After the mutated sites were confirmed by DNA sequencing, report gene assay was used to study the effects of Miy C and Kob A on the trans-activating ability of ER. Results indicated that the effect of Miy C on the trans-activating ability of mutant 1 of ER [M1ER (ER M(517)AG(521)D)] was decreased, and Kob A had no stimulating effects on the trans-activating ability of M1ER. Miy C and Kob A had no stimulating effects on the trans-activating ability of mutant 2 of ER [M2ER (ER E(353)GR(394)G)]. Therefore, the ER sites for Miy C and Kob A may be located at Glu(353), Arg(394), Met(517) and Gly(521).

EGR-1 gene promoter and CDglyTK gene were used to construct the pcDNA3-EGR-CDglyTK recombinant vector, in which CDglyTK gene expression was under the control of EGR-1 gene promoter. Cationic liposome LipofectAMINE was used to transfect plasmids into human hepatoma 7402 cell line. Subsequently, the transfected cells were treated with different doses of gamma-ray. Northern blot and Western blot showed that ionizing radiation can induce CDglyTK gene expression drived by EGR-1 promoter,in a dose-dependant manner. There was no ionizing radiation-inducible effect in pcDNA3-CMV-CDglyTK control group. Ionizing radiation also markedly enhanced the sensitivity of tumor cells transfected with pcDNA3-EGR-CDglyTK to prodrugs (GCV/5-FC) in tumor cell killing. The data indicated that EGR-1 promoter was inducible by ionizing radiation, whereas the CMV promoter was not. There was a synergetic effect between GCV and 5-FC. The cytotoxic effect of the suicide gene-ionizing radiation combination was stronger than suicide gene alone or ionizing radiation alone.

Activation of G-protein coupled muscarinic acetylcholine receptors and MAPKs/ERK-1/2 has been found to inhibit neural cell apoptosis and promote neural cell survival. Bcl-2 protein family also plays an important role in regulating neural cell apoptosis and survival. However, signaling pathways coupling muscarinic receptors to Bcl-2 family remains to be elucidated. In the present study, it was found that carbachol not only activated MEK/ERK-1/2 signaling pathways, but also increased the expression levels of Bcl-2 and phospho-Bad proteins in human neuroblastoma SH-SY5Y cells. These effects were blocked by a muscarinic receptor antagonist (atropine) and a MEK inhibitor(PD98059) and were significantly attenuated by a Src family kinases inhibitor(PP1) and a PKC inhibitor (bisindolymaleimide-I), but were not influenced by a G(i/o)-uncoupling reagent (pertussin toxin) and a PI-3 kinase inhibitor (wortmannin). Furthermore, carbachol also stimulated Bcl-2 promoter-driven luciferase gene expression in transfected SH-SY5Y cells. Co-transfection of Ras or Raf dominant negative mutants with the pBcl-2-Luc plasmid abolished carbachol s effects. These data suggested that muscarinic acetylcholine receptors regulated the expression of Bcl-2 protein family by Ras-ERK-1/2 signaling pathway involving the pertussin toxin-insensitive G-proteins, PKC and Src.

To explore the effect of LPS on the expression of CD14 and the activation of Kupffer cells (KCs).

To explore the influence of lanthanum chloride on the TNFalpha expression of murine peritoneal macrophages stimulated by lipopolysaccharide (LPS).

To investigate the protective effect and its underlying mechanism of 2,4-diamino-6-hydroxy-pyrimidine (DAHP), an inhibitor of GTP-cyclohydrolase I (GTP-CHI), on postburn Staphylococcus aureus (S. aureus) sepsis in rats.

To investigate the significance of the expression pattern and its signal modulating mechanism of endothelial ICAM-1 induced by LPS.

The purpose of this investigation was to study the variation of p73 gene expression in the apoptotic process of acute myeloid leukemia (AML) cell line U937 induced by methotrexate (MTX). Morphological changes of apoptotic cells were observed with microscopy and Wright's + Giemsa staining. DNA ladder and cell cycle were examined by agarose gel electrophoresis and flow cytometry respectively. Using semi-quantitive reverse transcription-polymerase chain reaction (RT-PCR), the expression of p73 mRNA was examined. Results showed that MTX could induce U937 cell apoptosis effectively. Condensed nuclei, fragmentation of chromosome and DNA ladder were seen after 6 hour following treatment of MTX 5 micro mol/L. Sub-G(1) peak and S + G(2)/M arrest were also determined by FCM, but the quantity of p73 expression was generally constant. In conclusion, U937 cell apoptosis induced by MTX did not change p73 mRNA level.

To explore the molecular mechanism of the synergetic effect of mitogen-activated protein kinase (MAPK) pathway on expression of tumor necrosis factor alpha (TFG-alpha) gene in murine monocyte (RAW264.7 cells) induced by lipopolysaccharide (LPS).

To explore the molecular mechanism of inducible nitric oxide synthase (iNOS) gene expression induced by lipopolysaccharide (LPS) in monocytes or macrophages.

To estimate the bystander effect mediated by herpes simplex virus-thymidine kanase/ganciclovir (HSV-TK/GCV) suicide gene therapy approach on PC-3m, a prostate cancer cell line, to explore the role of connexin (Cx) mediated gap junctional intercellular communication (GJIC) in the procedure of bystander effect of HSV-TK/GCV system and to investigate the modulation of apigenin, a Cx expression up-regulator on the connexin43 (Cx43) expression and GJIC of PC-3m cells.

To explore the effect of IFN-gamma and TNF-alpha on hepatitis B virus posttranscriptional regulatory elements.