ABSTRACT
The neoagaro-oligosaccharides, degraded from agarose by agarases, are important natural substances with many bioactivities. In this study, a novel agarase gene, agaW1540, from the genome of a deep-sea bacterium Shewanella sp. WPAGA9, was expressed, and the recombinant AgaW1540 (rAgaW1540) displayed the maximum activity under the optimal pH and temperature of 7.0 and 35 °C, respectively. rAgaW1540 retained 85.4% of its maximum activity at 0 °C and retained more than 92% of its maximum activity at the temperature range of 20-40 °C and the pH range of 4.0-9.0, respectively, indicating its extensive working temperature and pH values. The activity of rAgaW1540 was dramatically suppressed by Cu2+ and Zn2+, whereas Fe2+ displayed an intensification of enzymatic activity. The Km and Vmax of rAgaW1540 for agarose degradation were 15.7 mg/mL and 23.4 U/mg, respectively. rAgaW1540 retained 94.7%, 97.9%, and 42.4% of its maximum activity after incubation at 20 °C, 25 °C, and 30 °C for 60 min, respectively. Thin-layer chromatography and ion chromatography analyses verified that rAgaW1540 is an endo-acting ß-agarase that degrades agarose into neoagarotetraose and neoagarohexaose as the main products. The wide variety of working conditions and stable activity at room temperatures make rAgaW1540an appropriate bio-tool for further industrial production of neoagaro-oligosaccharides.
Subject(s)
Aquatic Organisms/chemistry , Sepharose/genetics , Shewanella/genetics , Animals , Bacterial Proteins/genetics , Cold Temperature , Hydrogen-Ion Concentration , TemperatureABSTRACT
We present the complete genome sequence of Bacillus sp. strain V3, which was isolated from mangrove sediments from Yanpu Bay, Wenzhou, China. The 4.44-Mb genome sequence of V3 will be useful for studying the functional genes with potential industrial application of this species from mangrove sediments.
ABSTRACT
In the present study, to investigate the expression of PinX1 gene and its functional effects in human esophageal carcinoma (Eca)-109 cell line, expression vectors of human PinX1 (pEGFP-C3-PinX1) and its small interfering RNA (PinX1-FAM-siRNA) were constructed and transfected into Eca-109 cells using Lipofectamine 2000. Firstly, the mRNA expression level of PinX1 was examined using reverse transcription-polymerase chain reaction (RT-PCR). Once successful transfection was achieved, the effects on the mRNA level of human telomerase reverse transcriptase (hTERT), telomerase activity, cell proliferation and apoptosis were examined by semi-quantitative RT-PCR, stretch PCR, MTT assay and flow cytometry, respectively. Analysis of restriction and sequencing demonstrated that the recombining plasmids were successfully constructed. The results also indicated that transfection with pEGFP-C3-PinX1 and PinX1-FAM-siRNA into Eca-109 cells significantly increased PinX1 mRNA, decreased hTERT mRNA by 29.9% (P<0.05), and significantly reduced telomerase activity (P<0.05), inhibited cell growth, and increased the cell apoptotic index from 19.27±0.76 to 49.73±2%. The transfected PinX1-FAM-SiRNA exhibited PinX1 mRNA expression levels that were significantly decreased by 70% (P<0.05), whereas the remaining characteristics of Eca-109 cells, including cell growth, mRNA level of hTERT, telomerase activity and cell apoptotic index were not altered. Exogenous PinX1 has been demonstrated to be highly expressed in human Eca. PinX1 can inhibit human telomerase activity and the expression of hTERT mRNA, reduce tumor cell growth and induce apoptosis. Notably, these inhibitory functions were inhibited by silencing PinX1 in Eca with PinX1-FAM-siRNA. PinX1 was successfully increased and decreased in the present study, demonstrating that it may be a potential telomerase activity inhibitor. As PinX1 is an endogenous telomerase inhibitor, it may be used as a novel tumor-targeted gene therapy.
ABSTRACT
Previous studies have demonstrated that the growth of tumor cells may be inhibited by antisense oligonucleotides (ASODNs) targeted against human telomerase (hTR) or human telomerase reverse transcriptase (hTERT), resulting in antitumor activity in a wide variety of tumors. However, few studies have investigated the effect of hTERT gene-targeted ASODNs on telomerase activity and cell proliferation in human esophageal cancer. In the present study, an MTT assay was used to determine the growth inhibition rate of Eca-109 cells treated with a hTERT-targeted phosphorothioate-ASODN (PS-ASODN). An inverted microscope was used to observe the morphologic changes of the cells following treatment with 5 µM PS-ASODN for 10 days. Telomerase activity was detected using the silver staining semi-quantitative telomeric repeat amplification protocol (TRAP) assay. Following treatment with the PS-ASODN (1-5 µmol/l), the proliferation of the Eca-109 cells was inhibited. The differences in inhibition rate between the PS-ASODN and blank control groups were statistically significant (P<0.05) when the concentration of the PS-ASODN was ≥2 µmol/l, whereas no statistically significant difference was identified between the non-specific-ASODN and blank control groups. The inhibition rate increased gradually as the concentration of the PS-ASODN increased and with time, suggesting that the PS-ASODN inhibited the growth of Eca-109 cells in a concentration-dependent, time-dependent and sequence-specific manner. The growth rate of the cells incubated with the PS-ASODN was reduced compared with that of the control cells. Cells treated with the PS-ASODN became round, suspended and reduced in size. The PS-ASODN was also found to inhibit telomerase activity. The ability of the PS-ASODN to inhibit the telomerase activity and cell proliferation of the Eca-109 cell line suggests that ASODNs have the potential to be novel therapeutic agents for the treatment of esophageal cancer.
ABSTRACT
OBJECTIVE: To systematically examine the post-marketing safety of depside salt injection made from Danshen (Radix Salviae Miltiorrhizae), identify the potential risk factors, and ensure its clinical safety. METHODS: We examined a comprehensive series of studies on the production process, quality standards, pharmacology, population pharmacokinetics, and safety evaluation of depside salt injection made from Danshen (Radix Salviae Miltiorrhizae). Data from I-IV clinical drug trials, hospital information systems (HIS), and spontaneous reporting systems (SRS) were also analyzed. RESULTS: The effective components of salvianolic acid salt content reached almost 100%, and the magnesium lithospermate B content reached more than 80%. The median lethal dose (LD50) calculated by the Bliss method was 1.49 g/kg, with 95% confidence intervals of 1.29-1.72 g/kg. Long-term tests on Beagle dogs indicated that doses of less than 80 mg/kg were safe and doses of 320 mg/kg were toxic. Adverse drug reactions (ADRs) included digestive disorders; drug-induced erythrocyte deformation in lung, liver, spleen, kidney, bone marrow, intestinal mucosa, lymph nodes, and other tissues; megakaryocytes in lung, liver, and spleen resulting from mild hemolysis; and mild hyperplasia in bone marrow hematopoietic tissue. Other studies indicated no irritative effect of the injection on local tissues and blood vessels, and no allergic reactions, erythrocyte coagulation, or hemolysis. SRS data showed that the most common ADRs were headache, head distention, dizziness, facial flushing, skin itching, thrombocytopenia, and the reversibility of elevated Aspartate transaminase. HIS data indicated no damage to renal function from using depside salt injection made from Danshen (Radix Salviae Miltiorrhizae) at a dosage higher than the recommended dose. CONCLUSION: This study analyzes the clinical characteristics of ADRs from depside salt injection made from Danshen (Radix Salviae Miltiorrhizae), and discusses the factors influencing such reactions. It provides scientific reference and recommendations for clinically safe medication of the Danshen injection.
