MicroRNA-451 regulates p38 MAPK signaling by targeting of Ywhaz and suppresses the mesangial hypertrophy in early diabetic nephropathy

Diabetic nephropathy (DN) is a major diabetic complication. However, the initiating molecular events triggering DN are unknown. In this study we focused on microRNA-451 (miR-451), which is downregulated during early DN. We found that miR-451 negatively regulated the expression of Ywhaz through Ywhaz 3'UTR and that Ywhaz was required for the miR-451-mediated downregulation of p38 MAPK signalling. Moreover, over-expression of miR-451 inhibits glomerular mesangial cell proliferation in vitro and in vivo. These findings suggest that the growth-inhibitory effect of miR-451 may be explained in part by miR-451-induced suppression of Ywhaz and p38 MAPK signalling, providing evidence for the potential role of miR-451 in early DN.     

High-level expression of a novel Penicillium endo-1,3(4)-β-d-glucanase with high specific activity in Pichia pastoris

A novel endo-1,3(4)-β-D-glucanase gene (bgl16C1) from Penicillium pinophilum C1 was cloned and sequenced. The 945-bp full-length gene encoded a 315-residue polypeptide consisting of a putative signal peptide of 18 residues and a catalytic domain belonging to glycosyl hydrolase family 16. The deduced amino acid sequence showed the highest identity (82%) with the putative endo-1,3(4)-β-glucanase from Talaromyces stipitatus ATCC 10500 and 60% identity with the characterized β-1,3(4)-glucanase from Paecilomyces sp. FLH30. The gene was successfully overexpressed in Pichia pastoris. Recombinant Bgl16C1 constituted 95% of total secreted proteins (2.61 g l?1) with activity of 28,721 U ml?1 in a 15-l fermentor. The purified recombinant Bgl16C1 had higher specific activity toward barley β-glucan (12,622 U mg?1) than all known glucanases and also showed activity against lichenan and laminarin. The enzyme was optimally active at pH 5.0 and 55°C and exhibited good stability over a broad acid and alkaline pH range (>85% activity at pH 3.0-7.0 and even 30% at pH 11.0). All these favorable enzymatic properties make it attractive for potential applications in various industries.     

A thermostable 5-enolpyruvylshikimate-3-phosphate synthase from Thermotoga maritima enhances glyphosate tolerance in Escherichia coli and transgenic Arabidopsis

Extremophiles - 5-Enolpyruvylshikimate-3-phosphate synthase (EPSPS) overexpression, attempting to provide excess EPSPS to combine with glyphosate, is one way to improve glyphosate resistance of...     

LINC01342 promotes the progression of ovarian cancer by absorbing microRNA-30c-2-3p to upregulate HIF3A

Ovarian cancer (OC) is a highly prevalent gynecologic malignancy and its mortality is extremely high. Therefore, the development of novel therapeutic approaches for OC is of great significance. In this study, LINC01342 was upregulated in OC tissue in the GSE38666 microarray and in tumor tissue samples collected in our center. The silencing of LINC01342 suppressed the proliferative and metastatic capacities of A2780 and HO8910 cells. Subcellular distribution assays showed that LINC01342 was mainly enriched in the cytoplasm. Subsequently, the downregulation of microRNA-30c-2-3p was proven to be the target of LINC01342. The silencing of microRNA-30c-2-3p enhanced the clonality and migratory capacity of OC cells. Moreover, the silencing of microRNA-30c-2-3p could reverse the inhibited migration and clonality in OC cells caused by LINC01342 knockdown. In addition, hypoxia-inducible factor 3 subunit α (HIF3A) was proven to be the target gene of microRNA-30c-2-3p, which was upregulated. HIF3A was negatively regulated by microRNA-30c-2-3p but positively regulated by LINC01342 in OC cells. An RNA binding protein immunoprecipitation assay showed that microRNA-30c-2-3p, LINC01342, and HIF3A could bind to argonaute RISC catalytic component 2. The overexpression of HIF3A reversed the inhibited migration and clonality in OC cells with LINC01342 knockdown. By analyzing the follow-up data from the enrolled OC patients, the LINC01342 and HIF3A levels were negatively correlated with prognosis, while the microRNA-30c-2-3p level was positively correlated with the same. In short, the upregulated LINC01342 in OC absorbs microRNA-30c-2-3p to release HIF3A. Thus, upregulated HIF3A expression accelerates the progression of OC.     

Effect of <Emphasis Type="Italic">poxB</Emphasis> gene knockout on metabolism in <Emphasis Type="Italic">Escherichia coli</Emphasis> based on growth characteristics and enzyme activities

The effect of poxB gene knockout on metabolism in Escherichia coli was investigated in the present paper based on the growth characteristics and the activities of the enzymes involved in the central metabolic pathways. The absence of pyruvate oxidase reduced the glucose uptake rate and cell growth rate, and increased O₂ consumption and CO₂ evolution. The enzyme assay results showed that although glucokinase activity increased, the flux through glycolysis was reduced due to the down-regulation of the other glycolytic enzymes such as 6-phosphofructosekinase and fructose bisphosphate aldolase in the poxB mutant. TCA cycle enzymes such as citrate synthase and malate dehydrogenase were repressed in the poxB mutant when the cells were cultivated in LB medium. The pyruvate oxidase mutation also resulted in the activation of glucose-6-phosphate dehydrogenase and acetyl-CoA synthetase. All these results suggest that pyruvate oxidase is not only a stationary-phase enzyme as previously known, and that the removal of the poxB gene affects the central metabolism at the enzyme level in E. coli.     

Environmental changes in Lake Taihu during the past century as recorded in sediment cores

The Lake Taihu drainage basin is an economically developed area with some of the highest population densities in China. The lake has deteriorated due to ecological destruction and eutrophication. Three short sediment cores from eastern, northeastern and southwestern Lake Taihu were collected. Total organic carbon (TOC), total nitrogen (TN), pigments, elements and particle size were analyzed for the purpose of understanding past trophic status and pollution levels. Sedimentation rates were based on ¹³⁷Cs or ²¹⁰Pb methods. Results indicated that sediment particle size became coarser since the 1920s, and the lake was contaminated by heavy metals, such as Cu and Zn, since the 1970s. A remarkable increase in eutrophication since the 1980s due to increased loading of untreated effluents from industry, agriculture and urbanization is reflected by total organic carbon, total nitrogen and pigments in the studied cores. However the onset times of eutrophication in different parts of Lake Taihu were not synchronous.     

Monoclonal antibody against non-dominant epitopes of HBV e Ag was raised by antigen-antibody co-immunization

Detection of hepatitis B e antigen (HBeAg) in the sera of individuals infected with hepatitis B virus (HBV) can indicate both a high infectivity of the disease and a poor prognosis of disease treatment. Most of monoclonal antibodies raised against HBV e proteins interact with immuno-dominant epitopes, such as HBeAg-beta. In order to raise antibodies against non-dominant epitopes of HBV e protein, in this study, mice were immunized with both recombinant HBeAg (rHBeAg) and an anti-HBeAg antibody (EWB) recognizing a dominant antigenic epitope of HBeAg (HBeAg-beta epitope). With this strategy, we successfully selected two monoclonal antibodies, S-29-3 and S-72-3. Both S-29-3 and S-72-3 bind to recombinant HBeAg with a high affinity. The epitope mapping assay determined that the S-73-2 recognizes the N-terminal of HBeAg (1-118 aa) and the S-29-3 recognizes the C-terminal of HBeAg (91-149 aa). Further experiment showed that these two antibodies could be formed a pair-Abs that is used in detecting native HBeAg from the sera of HBV patients. The conclusion is that the developed method is useful to raise mAb against non-dominant epitopes in given Ag.     

Function and oligomerization study of the leucine zipper-like domain in P13 from Leucania separata multiple nuclear polyhedrosis virus

The p13 gene is uniquely present in Group II nucleopolyhedroviruses (NPVs) and some granuloviruses, but not in Group I NPVs. p13 gene was first described by our laboratory in Leucania separatamultiple nuclear polyhedrosis virus (Ls-p13) in 1995. However, the functions of Ls-P13 and of its homologues are unknown. When Ls-p13 was inserted into Autographa californica nucleopolyhedrovirus, a Group I NPV, polyhedra yield was inhibited. However, this inhibition was prevented when the leucine zipper-like domain of Ls-p13 was mutated. To determine the cause of this marked difference between Ls-P13 and leucine zipper mutated Ls-P13 (Ls-P13mL), oligomerization and secondary structure analyses were performed. High performance liquid chromatography and yeast two-hybrid assays indicated that neither Ls-P13 nor Ls-P13mL could form oligomers. Informatics and circular dichroism spectropolarimetry results further indicated marked secondary structural differences between Ls-P13 and Ls-P13mL. The LZLD of Ls-P13 has two extended heptad repeat units which form a hydrophobic surface, but it is short of a third hydrophobic heptad repeat unit for oligomerization. However, the mutated LZLD of Ls-P13mL lacks the above hydrophobic surface, and its secondary structure is markedly different. This difference in its secondary structure may explain why Ls-P13mL is unable to inhibit polyhedra yield.