Effects of Thermobifida fusca cutinase-carbohydrate-binding module fusion proteins on cotton bioscouring

Previously, we presented a novel approach for increasing Thermobifida fusca cutinase adsorption on cotton fibers by fusing cutinase with a carbohydrate-binding module (CBM). A preliminary study showed that two fusion proteins, namely cutinase-CBM_Cel6A and cutinase-CBM_CenA, with similar stabilities and catalytic properties, had potential applications in bioscouring. In the present study, an indepth analysis of both cutinase-CBMs in bioscouring was explored. Effects of cutinase-CBMs on cotton bioscouring were investigated by characterizing the chemical and physical surface changes in enzyme-treated cotton fabrics. Gas chromatography/mass spectrometry was used to analyze the degradation of the cotton fabric cuticle; Fourier transform infrared microspectroscopy was used to study changes in the chemical composition of the cotton fabric epidermal layer; and scanning electron microscopy was used to monitor minor changes in the morphology of the fiber surface. Our results indicated that cutinase-CBMs in combination with pectinase had a greater effect on cotton fabric than did cutinase. Following scouring with cutinase-CBMs and pectinase, the performance of cotton fabric in terms of its wettability and dyeability was similar to that following alkali scouring. Our study provides a foundation for the further application of cutinase-CBM to bioscouring.     

Plant lectins: targeting programmed cell death pathways as antitumor agents

Lectins, a group of highly diverse, carbohydrate-binding proteins of non-immune origin that are ubiquitously distributed in plants, animals and fungi, are well-characterized to have numerous links a wide range of pathological processes, most notably cancer. In this review, we present a brief outline of the representative plant lectins including Ricin-B family, proteins with legume lectin domains and GNA family that can induce cancer cell death via targeting programmed cell death pathways. Amongst these above-mentioned lectins, we demonstrate that mistletoe lectins (MLs), Ricin, Concanavalin A (ConA) and Polygonatum cyrtonema lectin (PCL) can lead to cancer cell programmed death via targeting apoptotic pathways. In addition, we show that ConA and PCL can also result in cancer cell programmed death by targeting autophagic pathways. Moreover, we summarize the possible anti-cancer therapeutic implications of plant lectins such as ConA, Phaseolus vulgaris lectin (PHA) and MLs that have been utilized at different stages of preclinical and clinical trials. Together, these findings can provide a comprehensive perspective for further elucidating the roles of plant lectins that may target programmed cell death pathways in cancer pathogenesis and therapeutics. And, this research may, in turn, ultimately help cancer biologists and clinicians to exploit lectins as potential novel antitumor drugs in the future.     

Bacterial cellulose membrane – A new support carrier for yeast immobilization for ethanol fermentation

The aim of the work was to study the properties of the bacterial cellulose membrane (BCM) and the feasibility of using it as a new, environmentally friendly support carrier for yeast cell immobilization. It was observed that the morphology of BCM varied with different cultivation methods and the scanning electron microscopy (SEM) images confirmed that the yeast cells were entrapped in the porous network of BCM obtained from the static culture and stabilized by the cross-linked fibrils. Particularly, the research confirmed the effectiveness of yeast immobilization in BCM reflected by the high yield of alcohol (9.7% v/v, a 21.25% increase of those using free cells) and the high stability. The specific rate of ethanol production by the immobilized cells in BCM was 2.1 g g⁻¹ h⁻¹, 31.3% greater than that of the suspended cells. Results implied that applying BCM as the support carrier had little adverse effects on cell viability and proliferation. Instead, it facilitated the product leakage and nutrients transportation through the porous network.     

Cloning, expression and characterization of alcohol dehydrogenases in the silkworm Bombyx mori

Alcohol dehydrogenases (ADH) are a class of enzymes that catalyze the reversible oxidation of alcohols to corresponding aldehydes or ketones, by using either nicotinamide adenine dinucleotide (NAD) or nicotinamide adenine dinucleotide phosphate (NADP), as coenzymes. In this study, a short-chain ADH gene was identified in Bombyx mori by 5'-RACE PCR. This is the first time the coding region of BmADH has been cloned, expressed, purified and then characterized. The cDNA fragment encoding the BmADH protein was amplified from a pool of silkworm cDNAs by PCR, and then cloned into E. coli expression vector pET-30a(+). The recombinant His-tagged BmADH protein was expressed in E. coli BL21 (DE3), and then purified by metal chelating affinity chromatography. The soluble recombinant BmADH, produced at low-growth temperature, was instrumental in catalyzing the ethanol-dependent reduction of NAD(+), thereby indicating ethanol as one of the substrates of BmADH.     

Fine-scale spatial genetic structure and gene flow in a small, fragmented population of Sinojackia rehderiana (Styracaceae), an endangered tree species endemic to China

Populations of Sinojackia rehderiana are highly threatened and have small and scattered distribution due to habitat fragmentation and human activities. Understanding changes in genetic diversity, the fine-scale spatial genetic structure (SGS) at different life stages and gene flow of S. rehderiana is critical for developing successful conservation strategies for fragmented populations of this endangered species. In this study, 208 adults, 114 juveniles and 136 seedlings in a 50 × 100-m transect within an old-growth forest were mapped and genotyped using eight microsatellite makers to investigate the genetic diversity and SGS of this species. No significant differences in genetic diversity among different life-history stages were found. However, a significant heterozygote deficiency in adults and seedlings may result from substantial biparental inbreeding. Significant fine-scale spatial structure was found in different life-history stages within 19 m, suggesting that seed dispersal mainly occurred near a mother tree. Both historical and contemporary estimates of gene flow (13.06 and 16.77 m) indicated short-distance gene dispersal in isolated populations of S. rehderiana. The consistent spatial structure revealed in different life stages is most likely the result of limited gene flow. Our results have important implications for conservation of extant populations of S. rehderiana. Measures for promoting pollen flow should be taken for in situ conservation. The presence of a SGS in fragmented populations implies that seeds for ex situ conservation should be collected from trees at least 19-m apart to reduce genetic similarity between neighbouring individuals.     

Ordered Hierarchical Mesoporous/Microporous Carbon Derived from Mesoporous Titanium‐Carbide/Carbon Composites and its Electrochemical Performance in Supercapacitor

Novel ordered hierarchical mesoporous/microporous carbon (OHMMC) derived from mesoporous titanium‐carbide/carbon composites was prepared for the first time by synthesizing ordered mesoporous nanocrystalline titanium‐carbide/carbon composites, followed by chlorination of titanium carbides. The mesostructure and microstructure can be conveniently tuned by controlling the TiC contents of mesoporous TiC/C composite precursor, and chlorination temperature. By optimal condition, the OHMMC has a high surface area (1917 m²g^?1), large pore volumes (1.24 cm³g^?1), narrow mesopore‐size distributions (centered at about 3 nm), and micropore size of 0.69 and 1.25 nm, and shows a great potential as electrode for supercapacitor applications: it exhibits a high capacitance of 146 Fg^?1 in noaqueous electrolyte and excellent rate capability. The ordered mesoporous channel pores are favorable for retention and immersion of the electrolyte, providing a more favorable path for electrolyte penetration and transportation to achieve promising rate capability performance. Meanwhile, the micropores drilled on the mesopore‐walls can increase the specific surface area to provide more sites for charge storage.     

Impaired thymic export and apoptosis contribute to regulatory T-cell defects in patients with chronic heart failure

Objective

Animal studies suggest that regulatory T (T_reg) cells play a beneficial role in ventricular remodeling and our previous data have demonstrated defects of T_reg cells in patients with chronic heart failure (CHF). However, the mechanisms behind T_reg-cell defects remained unknown. We here sought to elucidate the mechanism of T_reg-cell defects in CHF patients.

Methods and Results

We performed flow cytometry analysis and demonstrated reduced numbers of peripheral blood CD4⁺CD25⁺FOXP3⁺CD45RO⁻CD45RA⁺ naïve T_reg (nT_reg) cells and CD4⁺CD25⁺FOXP3⁺CD45RO⁺CD45RA⁻ memory T_reg (mT_reg) cells in CHF patients as compared with non-CHF controls. Moreover, the nT_reg/mT_reg ratio (p<0.01), CD4⁺CD25⁺FOXP3⁺CD45RO⁻ CD45RA⁺CD31⁺ recent thymic emigrant T_reg cell (RTE-T_reg) frequency (p<0.01), and T-cell receptor excision circle levels in T_reg cells (p<0.01) were lower in CHF patients than in non-CHF controls. Combined annexin-V and 7-AAD staining showed that peripheral T_reg cells from CHF patients exhibited increased spontaneous apoptosis and were more prone to interleukin (IL)-2 deprivation- and CD95 ligand-mediated apoptosis than those from non-CHF individuals. Furthermore, analyses by both flow cytometry and real-time polymerase chain reaction showed that T_reg-cell frequency in the mediastinal lymph nodes or Foxp3 expression in hearts of CHF patients was no higher than that of the non-CHF controls.

Conclusion

Our data suggested that the T_reg-cell defects of CHF patients were likely caused by decreased thymic output of nascent T_reg cells and increased susceptibility to apoptosis in the periphery.