Density alteration in non-physiological cells

In the present study an important phenomenon of cells was discovered: the change of intracellular density in cell's response to drug and environmental factors. For convenience, this phenomenon is named as "density alteration in non-physiological cells" ( DANCE). DANCE was determined by discontinuous sucrose gradient centrifugation (DSGC), in which cells were separated into several bands. The number and position of the bands in DSGC varied with the change of cell culture conditions, drugs, and physical process, indicating that cell's response to these factors was associated with alteration of intracellular density. Our results showed that the bands of cells were molecularly different from each other, such as the expression of some mRNAs. For most cells tested, intracellular density usually decreased when the cells were in bad conditions, in presence of drugs, or undergoing pathological changes. However, unlike other tissue cells, brain cells showed increased intracellular density in 24 hrs after the animal death. In addition, DANCE was found to be related to drug resistance, with higher drug-resistance in cells of lower intracellular density. Further study found that DANCE also occurred in microorganisms including bacteria and fungus, suggesting that DANCE might be a sensitive and general response of cells to drugs and environmental change. The mechanisms for DANCE are not clear. Based on our study the following causes were hypothesized: change of metabolism mode, change of cell membrane function, and pathological change. DANCE could be important in medical and biological sciences. Study of DANCE might be helpful to the understanding of drug resistance, development of new drugs, separation of new subtypes from a cell population, forensic analysis, and importantly, discovery of new physiological or pathological properties of cells

Yield enhancement of recombinant α-Amylases in Bacillus amyloliquefaciens by ARTP mutagenesis-screening and medium optimization

α-Amylase is the most extensively applied enzyme in industry. There is an urgent need for improvement on the yield of α-amylases currently. Herein, a strategy which combined Atmospheric and Room Temperature Plasma (ARTP) mutagenesis tool for construction of mutant library of Bacillus amyloliquefaciens with a 24-well plates screening technique was adopted to improve the yield of recombinant Bacillus amyloliquefaciens α-amylases (BAA). A mutant strain named B. amyloliquefaciens ZN mut-7# was obtained, and the activity of BAA produced by this mutant strain was 86.92% higher than that of the original strain. B. amyloliquefaciens ZN mut-7# has an unchanged BAA gene and genetic stability. This successful application proved that ARTP can be applied to the genetically engineering strains that contain recombinant plasmid. Furthermore, response surface methodology offers an achievable and efficient strategy to optimize the composition of medium used to generate BAA in B. amyloliquefaciens ZN mut-7#. A 1.28-fold increase had been obtained compared to the production of non-optimized fermentation medium. This study demonstrates that ARTP mutagenesis and medium optimization are efficient and feasible methods for increasing recombinant enzyme production in the genetically engineering strains

Paternal Origin of Mongolic-Speaking Populations: A Review of Studies from Recent Decades (1999–2019) and their Implications for Multidisciplinary Research in the Future

The activities of Mongolic-speaking populations, a large group of people in eastern Eurasia, have important impact on the history of East Asia and other parts of Eurasia. Most previous genetic research of East Asian populations, including ancient DNA studies, have involved samples from Mongolic-speaking populations or their ancient relatives. Here, we summarized frequency data of paternal Y-chromosome haplogroups from all available literature about Mongolic-speaking populations from 1999 to 2019. Fourteen paternal components were identified and six of them were proposed as major and common components in ancestor groups of Mongolic-speaking populations. We thoroughly discussed the possible origin, migration patterns, and the roles of these six components in the evolution history of Mongolic-speaking populations. Meanwhile, we discussed the implications of the present achievements of human genetics for multidisciplinary research in ethnology, history, archaeology and linguistics in the future

Efficient Chemoenzymatic Synthesis of an N-glycan Isomer Library

Quantification, characterization and biofunctional studies of N-glycans on proteins remain challenging tasks due to the complexity, diversity and low abundance of these glycans. The availability of structurally defined N-glycan (especially isomer) libraries is essential to help solve these tasks. We report herein an efficient chemoenzymatic strategy, namely Core Synthesis/Enzymatic Extension (CSEE), for rapid production of diverse N-glycans. Starting with 5 chemically prepared building blocks, 8 N-glycan core structures containing one or two terminal N-acetyl-D-glucosamine (GlcNAc) residue(s) were chemically synthesized via consistent use of oligosaccharyl thioethers as glycosylation donors in a convergent fragment coupling strategy. Each of these core structures was then extended to 5 to 15 N-glycan sequences by enzymatic reactions catalyzed by 4 robust glycosyltransferases. Success in synthesizing N-glycans with Neu5Gc and core-fucosylation further expanded the ability of the enzymatic extension. Meanwhile, high performance liquid chromatography with an amide column enabled rapid and efficient purification (\u3e98% purity) of N-glycans in milligram scales. A total of 73 N-glycans (63 isomers) were successfully prepared and characterized by MS2 and NMR. In summary, the CSEE strategy provides a practical approach for “mass production” of structurally defined N-glycans, which are important standards and probes for glycoscience

THE PROTECTIVE EFFECTS OF CASSAVA ( MANIHOT ESCULENTA CRANTZ ) LEAF FLAVONOID EXTRACTS ON LIVER DAMAGE OF CARBON TETRACHLORIDE INJURED MICE

Background: Cassava leaf contains many kinds of flavonoids, most of flavonoids function as effective antioxidants in vivo. The protective effects of cassava (Manihot esculenta Crantz) leaf flavonoid extracts on liver damage were evaluated by carbon tetrachloride (CCl4)-induced injury in mice. Materials and methods: The protective effects of cassava leaf flavonoid extracts on liver damage were evaluated using CCl4-induced injury in mice. The mice were weighted to calculate sample quantity of mice. Bloods were taken to evaluate ALT and AST of serums. Livers were excised and weighted, and fixed for pathological observation. Prepared 10% liver tissue homogenate was used to evaluate MDA, SOD, GSH-PX levels. Results: Cassava leaf flavonoid extracts significantly decreased (p < 0.05) the relative liver weight when compared with the CCl4-treated group. The contents of ALT and AST in serum of experiment mice declined significantly when compared to those of the CCl4-treated group, but did not reach normal levels of control group. Pathological observation of livers showed that cassava leaf flavonoid extracts significantly ameliorated the CCl4-induced pathological changes. Conclusion These results provided biological evidence that cassava leaf flavonoid extracts indeed expressed potential efficacy of prohibiting liver injury in mice

Cancer-induced bone pain sequentially activates the ERK/MAPK pathway in different cell types in the rat spinal cord

<p>Abstract</p> <p>Background</p> <p>Previous studies have demonstrates that, after nerve injury, extracellular signal-regulated protein kinase (ERK) activation in the spinal cord-initially in neurons, then microglia, and finally astrocytes. In addition, phosphorylation of ERK (p-ERK) contributes to nociceptive responses following inflammation and/or nerve injury. However, the role of spinal cells and the ERK/MAPK pathway in cancer-induced bone pain (CIBP) remains poorly understood. The present study analyzed activation of spinal cells and the ERK/MAPK pathway in a rat model of bone cancer pain.</p> <p>Results</p> <p>A Sprague Dawley rat model of bone cancer pain was established and the model was evaluated by a series of tests. Moreover, fluorocitrate (reversible glial metabolic inhibitor) and U0126 (a MEK inhibitor) was administered intrathecally. Western blots and double immunofluorescence were used to detect the expression and location of phosphorylation of ERK (p-ERK). Our studies on pain behavior show that the time between day 6 and day 18 is a reasonable period ("time window" as the remaining stages) to investigate bone cancer pain mechanisms and to research analgesic drugs. Double-labeling immunofluorescence revealed that p-ERK was sequentially expressed in neurons, microglia, and astrocytes in the L4-5 superficial spinal cord following inoculation of Walker 256 cells. Phosphorylation of ERK (p-ERK) and the transcription factor cAMP response element-binding protein (p-CREB) increased in the spinal cord of CIBP rats, which was attenuated by intrathecal injection of fluorocitrate or U0126.</p> <p>Conclusions</p> <p>The ERK inhibitors could have a useful role in CIBP management, because the same target is expressed in various cells at different times.</p

Periostin as a promising target of therapeutical intervention for colorectal cancer

The expression of periostin in the tissue of colorectal cancer patients and its correlation with clinical features were studied. Periostin expression was ~4 fold up-regulated in cancer tissues compared to adjacent non-cancerous tissues. Serum levels of periostin in patients were significantly elevated to 32.6 ± 10.8 ng/mL vs 20.4 ± 11.1 ng/mL in healthy volunteers. Higher preoperative serum periostin levels in patients were closely related to advanced-stage disease (stage III/IV), distant and lymph nodes metastasis. High level of periostin expression was detected in the SW480 human colon carcinoma cells, and could be down-regulated by small interfering RNAs (siRNA). The siRNA-mediated knockdown of periostin arrested the cell cycle at G0/G1 phase and induced apoptotic cell death in the SW480 cells. In conclusion, periostin is a promising prognostic and therapeutic target for colorectal cancer

Synthesis, characterization and property of a mixed-valent Ag-I/Ag-II coordination polymer

A novel mixed-valent Ag-I/Ag-II coordination polymer {[(Ag2Ag0.5II)-Ag-I(SO4)(HSO4)(pyz)(2.5)]center dot H2O}(n) (1, pyz = pyrazine) was synthesized and characterized. The results show it presents semiconducting and photoluminescent properties.National Natural Science Foundation of China [20721001]; MSTC [2007CB815301]; National Science Fund of China for Fostering Talents in Basic Science [J0630429