Chemically Cross-Linked Hammerhead Ribozyme as an Efficient RNA Interference Tool.

RNA-cleaving ribozymes are promising candidates as general tools of RNA interference (RNAi) in gene manipulation. However, compared with other RNA systems, such as siRNA and CRISPR technologies, the ribozyme tools are still far from broad applications on RNAi due to their poor performance in the cellular context. In this work, we report an efficient RNAi tool based on chemically modified hammerhead ribozyme (HHR). By the introduction of an intramolecular linkage into the minimal HHR to reconstruct the distal interaction within the tertiary ribozyme structure, this cross-linked HHR exhibits efficient RNA substrate cleavage activities with almost no sequence constraint. Cellular experiments suggest that both exogenous and endogenous RNA expression can be dramatically knocked down by this HHR tool with levels comparable to those of siRNA. Unlike the widely applied protein-recruiting RNA systems (siRNA and CRISPR), this ribozyme tool functions solely on RNA itself with great simplicity, which may provide a new approach for gene manipulation in both fundamental and translational studies.

Is HFPO-DA (GenX) a suitable substitute for PFOA? A comprehensive degradation comparison of PFOA and GenX via electrooxidation.

Due to the potential hazard of perfluorooctanoic acid (PFOA), hexafluoropropylene oxide dimer acid (HFPO-DA, GenX) has become a typical alternative since 2009. However, GenX has recently been reported to have equal or even greater toxicity and bioaccumulation than PFOA. Considering the suitability of alternatives, it is quite essential to study and compare the degradation degree between PFOA and GenX in water. Therefore, in the present study, a comprehensive degradation comparison between them via electrooxidation with a titanium suboxide membrane anode was conducted. The degradation rate decreased throughout for PFOA, while it first increased and then decreased for GenX when the permeate flux increased from 17.3 L to 100.3 L m-2·h-1. The different responses of PFOA and GenX to flux might be attributed to their different solubilities. In addition, the higher kobs of PFOA demonstrated that it had a better degradability than GenX by 2.4-fold in a mixed solution. The fluorinated byproduct perfluoropropanoic acid (PFPrA) was detected as a GenX intermediate, suggesting that ether bridge splitting was needed for GenX electrooxidation. This study provides a reference for assessing the degradability of GenX and PFOA and indicates that it is worth reconsidering whether GenX is a suitable alternative for PFOA from the point of view of environmental protection.

Antiproliferative and immunostimulatory activity of a protein from Pleurotus eryngii.

BACKGROUND: Currently, the use of mushrooms as functional foods, nutraceuticals or phytopharmaceuticals source has risen. In contrast, the possible cellular cytotoxicity and immunostimulatory activity of Pleurotus eryngii (DC. ex Fr.) Quel protein (PEQP) is unknown. Here we report extraction, anti-tumorigenic and immunostimulatory activity of PEQP in vitro. RESULTS: PEQP was extracted from the dried fruiting bodies of P. eryngii, purified and characterised. Its in vitro antiproliferative activity was then evaluated in human non-small cell lung cancer A549 (NSCLC), stomach adenocarcinoma BGC-823, hepatocellular carcinoma HepG2 and gastric carcinoma HGC-27 cell lines using conventional cancer drugs (paclitaxel, doxorubicin and mitomycin C) as positive controls. The protein fractions (PEQP 1, 2, 3 and 4) obtained inhibited tumour cell proliferation dose-dependently with fraction PEQP 2 having significant (P < 0.05) toxicity in all tumour cells. PEQP had no significant toxicity on normal liver Chang cells but their proliferation was significantly inhibited by mitomycin C. Moreover, PEQP stimulated the proliferation, lysosomal enzyme activity, pinocytosis, nitric oxide and hydrogen peroxide production of RAW 264.7 cell lines dose-dependently. CONCLUSION: Based on these results, P. eryngii protein has a potential application in functional foods as a natural anti-tumour agent with immunostimulatory activity.

Analytical and experimental analysis of concrete temperature and energy considering open-air environmental variations.

Longwave radiation is an important open-air environmental factor that can significantly affect the temperature of concrete, but it has often been ignored in the temperature analysis of open-air concrete structures. In this article, an improved analytical model of concrete temperature was proposed by considering solar radiation, thermal convection, thermal conduction and especially longwave radiation. Temperature monitoring of an open-air concrete block was carried out to verify the proposed model and analyze the heat energy characteristics of open-air concrete. As demonstrated by the open-air experiment, under the influence of longwave radiation, the temperature at the top of the concrete block could decrease rapidly at night and even become lower than the minimum temperature at its bottom. Compared with the analytical model that ignores longwave radiation, the improved model that includes it better matches the measured temperature. According to the energy analysis, although solar radiation controls the transient variation in heat energy, the heat exchange caused by longwave radiation were more than that caused by convection on sunlit surfaces, which indicates the importance of considering longwave radiation.

Combined effects of ultrasound and antioxidants on the quality maintenance of bay scallop (Argopecten irradians) adductor muscles during cold storage.

The combined effects of ultrasound and the antioxidants of bamboo leaves (AOB) on the quality maintenance of the adductor muscle of scallops (AMSs) during cold storage was investigated. Ultrasound power at 350 W coupled with AOB solution (2% w/v) (UAOB-350) was applied to treat the AMSs according to Taylor diagram analysis. The microstructure, oxidative changes (lipid and protein oxidation), total numbers of colonies, total volatile basic nitrogen, and texture of the AMSs during 6 days of cold storage were analysed. The results indicated that UAOB-350 treatment could effectively retard protein and lipid oxidation and bacterial growth and maintain better microstructure and texture characteristics than AOB solution treatment alone, prolonging the shelf life of the AMSs by 2 days during storage at 4 °C. These results indicate that the UAOB-350 combination method has promising potential to maintain the quality and extend the shelf life of AMSs during cold storage.

Effects of polysaccharides from the base of Flammulina Velutipes stipe on growth of murine RAW264.7, B16F10 and L929 cells.

A polysaccharide (FVSP) was isolated from the base of Flammuliana Velutipes stipe, and FVSP was further purified by DEAE-cellulose-52 chromatography and Sephadex G-100 size-exclusion chromatography to obtain three fractions named FVSP-1, FVSP-2 and FVSP-3. Then their activation of macrophage cell RAW 264.7 and anti-proliferative effects to the murine melanoma B16F10 and fibroblasts L929 cells were evaluated by using the cell model experiments. The results indicated that the polysaccharide fractions could increase the proliferation and phagocytic activity of macrophage significantly and play an inhibited effect on the cancer cells. Moreover, the anti-proliferative activities of FVSPs increased with the participation of the antitumor factors induced from macrophage by polysaccharides fractions. Taken together, these results indicated that three polysaccharides fractions from the base of F. Velutipes stipe may be useful as potent antitumor agents for the prevention of tumorigenesis.

Variation of volatile terpenes in the edible fungi mycelia Flammulina velutipes and communications in fungus-mite interactions.

Many mites rely on fungi for nutrients, and fungi benefit from them with regard to spore dispersal, or nutrient resources. The interactions among mites and fungi are still not clear in most cases. This study analyzed volatile natural products from the liquid and solid cultures of the edible fungi, Flammulina velutipes (Fr.) Sing, and the solid mycelia induced by the storage mite, Tyrophagus putrescentiae Schrank, using HS-SPME-GC-MS/MS. Five new monoterpenes and 30 new sesquiterpenes were isolated from the two cultures of F. velutipes and a newly monoterpene and 14 newly sesquiterpenes found in the solid mycelia induced by the storage mite. Sesquiterpenes were abundant in the mycelial stage of F. velutipe. The mite was attracted by some volatiles from host fungi, dihydrocarveol, cedrol, ß-caryophyllene, α-terpilene, ß-pinene and benzaldehyde, analyzed by four-arm olfactometer. Some terpenes induced by T. putrescentiae, such as caryophyllene oxide, bicyclogermacrene, and (-)-spathulenol, would have potential biological function. These results suggest that some volatile sesquiterpenes play an important role in enabling the mite to recognize host fungi.

Effects of stem cell therapy on dilated cardiomyopathy.

OBJECTIVES: To perform a meta-analysis of clinical trials and investigate the effect of stem cell therapy on dilated cardiomyopathy. METHODS: A systematic literature search was carried out between May 2012 and July 2013 in PubMed, Medline, Cochrane Library, and Excerpta Medica Database (EMBASE). The study took place in the Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China. The weighted mean difference (WMD) was calculated for left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), mortality and heart transplantation, and the 6-minute walk test (6-MWT) distance using the RevMan 5.0 software. RESULTS: Seven trials with 599 participants evaluated the association between the stem cell therapy and control groups. Compared with the control group, stem cell therapy group improved the LVEF (WMD: 3.98%, 95% confidence interval [CI]: 0.55 - 7.41%, p=0.02) and the 6-MWT distance (WMD: 132.12 m, 95% CI: 88.15-176.09 m, p<0.00001), and reduced mortality and heart transplantation (odds ratio [OR]: 0.48, 95% CI: 0.29-0.80, p=0.005). However, the LVEDD showed no significant difference between the 2 groups (WMD: -1.53 mm, 95% CI: -1.15-0.10 mm, p=0.10). CONCLUSION: This meta-analysis demonstrated that stem cell therapy improves cardiac function and reduces mortality in dilated cardiomyopathy patients, which suggested that stem cell therapy may represent a new therapy option for dilated cardiomyopathy. 

Immunopotentiation of Pleurotus eryngii (DC. ex Fr.) Quel.

ETHNOPHARMACOLOGICAL RELEVANCE: Pleurotus eryngii (DC. ex Fr.) Quel has been collected from the wild, cultivated and used in traditional medicines to treat various disorders and diseases since antiquity. In traditional Chinese medicine, the powdered fruiting bodies of Pleurotus eryngii were used for immunostimulation, skin-care, wound-healing, cancer and lumbago treatment. In the current study, we investigated the antiproliferative activity of Pleurotus eryngii powder on A549, BGC-823, HepG2 and HGC-27 cancer cells and its immunomodulating activity on macrophage, RAW 264.7 cells based on its active compound. MATERIALS AND METHODS: A novel bioactive protein (PEP) was extracted from Pleurotus eryngii fruiting bodies powder and purified on DEAE-52, CM-52 and Superdex 75 column chromatographies using an ÄKTA purifier. Its cytotoxicity on A549, BGC-823, HepG2, HGC-27 and RAW 267.4 cell lines was then evaluated using MTT, alamar blue (AB), trypan blue (TB), neutral red (NR), lactate dehydrogenase (LDH), Annexin V FITC/PI and morphological change assays. Moreover, lysosomal enzyme activity, pinocytosis, nitric oxide (NO) and hydrogen peroxide (H2O2) production assays were used to examine immunomostimulatory activity of PEP on RAW 267.4 cells. RESULTS: Based on high performance gel permeation chromatography (HPGPC), Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) analyses, the isolated protein (PEP) had a molecular weight of 63 kDa, a secondary (α-helical) structure and was mainly composed of arginine, serine and glycine. PEP significantly (P<0.05) inhibited A549, BGC-823, HepG2 and HGC-27 tumor cells proliferation dose-dependently with an IC50 range of 36.5 ± 0.84 to 229.0 ± 1.24 µg/ml. Contrarily, PEP stimulated the proliferation of macrophages. CONCLUSION: Pleurotus eryngii fruiting bodies powder has a potential application as a natural antitumor agent with immunomodulatory activity, proposedly, by targeting the lysosomes of cancerous cells and stimulating macrophage-mediated immune responses.

Synergistic antioxidant activities of eight traditional Chinese herb pairs.

Many Chinese therapeutic herbs that are traditionally used in combination demonstrate significantly better pharmacological effects when used in the combination than when used alone. However, the pharmacological mechanism for this synergism is still not well understood. In the present study, the antioxidant activities of six herbs ((Paeonia lactiflora (PL), Atractylodes macrocephala (AMA), Angelica sinensis (AS), Astragalus membranaceus (AME), Glycyrrhiza uralensis (GU) and Rheum officinale (RO)), which were historically combined into eight traditional Chinese herb pairs (TCHPs) (AME-AS, AME-AMA, AME-RO, AME-GU, AME-PL, PL-AS, PL-AMA and PL-GU), were investigated in vitro by assessing the 1,1-diphenyl-2-picryl hydrazine (DPPH)-radical scavenging abilities of the herbs. The results of this study showed that all eight TCHPs had a significantly larger scavenging capacity than would be expected from the theoretical sum of those of the respective constituent herbs (p<0.05). Furthermore, the AME-GU, AME-PL and AME-AMA pairs not only showed a significant synergistic effect in the DPPH scavenging assay, but they also demonstrated similar results in hydroxyl radical and superoxide radical anion scavenging assays. Interestingly, the AME-AMA combination had a significantly higher superoxide anion (0.2 g/ml) and hydroxyl radical scavenging ability than the AME or AMA. The changes in the total phenolic and flavonoid contents were also investigated. Our study showed a significant correlation between the rate of enhancement in antioxidant capacity and the rate of increase in flavonoid content. Thus, the flavonoids are likely responsible for the synergistic effects present in TCHPs.