Pig IFITMs are restriction factors for Japanese encephalitis virus

Objective:Japanese encephalitis virus (JEV) is responsible for one of the most serious epidemics of encephalitis in the world. JEV uses pigs as its main hosts and spreads among vertebrates and humans mediated by Culex mosquitoes. The prevention and control of JEV spread in pigs is one of the most effective measures to protect global public health. Interferon-inducible transmembrane proteins (IFITMs) are small membrane-spanning proteins that were identified as innate antiviral factors against multiple pathogenic viruses, especially enveloped viral pathogens. This study aims to verify whether pig interferon-inducible transmembrane proteins (pIFITMs) inhibit JEV and investigate the related molecular mechanisms of anti-JEV.Methods:Transient expression and RNA interference technology were used to overexpress and silence IFITMs gene. Three different cell lines, PK15, HEK293 and Huh7, were transfected with recombinant pIFITMs-expressing plasmids. The lentiviral vectors harboring RNAi sequences targeting pIFITMs were introduced into PK15 cells. Quantitative real-time PCR was used to determine the antiviral activities of pIFITMs through measuring and analyzing the virus copy number of JEV (SA14-14-2 strain) in the supernant of pIFITMs overexpression or silencing cells 48 hours post transfection. The expression of the related proteins was examined by western blot. The fusion vectors inserted with pig IFITM1-EGFP were constructed and introduced into three different cell lines respectively. Then Laser Co-focus light microscopy was used to observe the subcellular localization. The key active amino acids of pIFITM1 were analyzed by investigating the anti-JEV effect of the cysteine mutants produced with PCR site directed mutagenesistechnology.Results:In three different cell lines, PK15, HEK293 and Huh7, all of three pig IFITM proteins, pIFITM1, pIFITM2, and pIFITM3 could inhibit the replication of JEV whether through transient gene over-expression methods or RNA interference silencing. And that, among three pig IFITMs, pIFITM1 showed the strongest anti-JEV effect. The anti-JEV activity of pIFITM1 manifested at the early entry stage. In PK15, BHK21, and HEK293 cells, before virus infection, pIFITM1 was located in the plasma membrane area, and after infection, transferred to the membranous structures outside the nucleus. The S-palmitoylated cysteines at position 50, 51 and 84 of pIFITM1 had significant effect on virus replication.Conclusions:Pig interferon-inducible transmembrane proteins are restriction factors for JEV infection and have potentials in the prevention of virus spread. Our results provide some new sights into understanding the antiviral activity of pig IFITMs.

Analysis on intestinal absorption of paeoniflorin lipid liquid crystalline nanoparticles via everted intestinal sacs / 中国中药杂志

To study the absorption kinetics of paeoniflorin lipid liquid crystalline nanoparticles (Pae-LLCN) in different intestinal segments of rats and compare them with paeoniflorin(Pae) solution. Rat everted gut sac models were adopted for intestinal absorption test, and Pae content was determined by HPLC method to study the absorption characteristics of Pae-LLCN in rat duodenum, jejunum, ileum and colon, and investigate the effects of different drug concentrations on intestinal absorption. Results showed that Pae-LLCN and Pae were well absorbed at different intestine segments and different concentrations. The absorption constant Ka was increased with the increasing of the drug concentration, indicating possible passive absorption. The accumulative absorption volume Q and absorption constant Ka of Pae-LLCN were higher than those of Pae at each intestinal segment(P<0.05). The results revealed that Pae-LLCN and Pae could be well absorbed in whole intestinal segments and its mechanism may be passive absorption. LLCN can effectively improve the intestinal absorption of Pae.

Characterization and evaluation in vivo of baicalin-nanocrystals prepared by an ultrasonic-homogenization-fluid bed drying method / 中国天然药物

AIM@#To improve the absorption and bioavailability of baicalin using a nanocrystal (or nanosuspension) drug delivery system.@*METHODS@#A tandem, ultrasonic-homogenization-fluid bed drying technology was applied to prepare baicalin-nanocrystal dried powders, and the physicochemical properties of baicalin-nanocrystals were characterized by scanning electron microscopy, photon correlation spectroscopy, powder X-ray diffraction, physical stability, and solubility experiments. Furthermore, in situ intestine single-pass perfusion experiments and pharmacokinetics in rats were performed to make a comparison between the microcrystals of baicalin and pure baicalin in their absorption properties and bioavailability in vivo.@*RESULTS@#The mean particle size of baicalin-nanocrystals was 236 nm, with a polydispersity index of 0.173, and a zeta potential value of -34.8 mV, which provided a guarantee for the stability of the reconstituted nanosuspension. X-Ray diffraction results indicated that the crystallinity of baicalin was decreased through the ultrasonic-homogenization process. Physical stability experiments showed that the prepared baicalin-nanocrystals were sufficiently stable. It was shown that the solubility of baicalin in the form of nanocrystals, at 495 μg·mL(-1), was much higher than the baicalin-microcrystals and the physical mixture (135 and 86.4 μg·mL(-1), respectively). In situ intestine perfusion experiments demonstrated a clear advantage in the dissolution and absorption characteristics for baicalin-nanocrystals compared to the other formulations. In addition, after oral administration to rats, the particle size decrease from the micron to nanometer range exhibited much higher in vivo bioavailability (with the AUC(0-t) value of 206.96 ± 21.23 and 127.95 ± 14.41 mg·L(-1)·h(-1), respectively).@*CONCLUSION@#The nanocrystal drug delivery system using an ultrasonic-homogenization-fluid bed drying process is able to improve the absorption and in vivo bioavailability of baicalin, compared with pure baicalin coarse powder and micronized baicalin.

Study on rational daily administration frequency of Fufang Biejia Ruangan tablet based on integrated serum pharmacologic and pharmacokinetic model / 中国中药杂志

To observe in vitro the effect of rat drug serum on the proliferation of HSC-T6 hepatic stellate cells in the pharmacokinetic model for determining peoniflorin in Fufang Biejia Ruangan tablet, in order to discover the rational daily administration frequency of Fufang Biejia Ruangan tablet. Fufang Biejia Ruangan tablet was orally administered to rats with different daily administration frequency. Their blood was collected from veins behind eye sockets at different time points before the administration and after the first administration, in order to determine the concentration of peoniflorin in blood plasma and the effect of rat drug serums on the proliferation of HSC-T6. A comprehensive analysis was made on the relationship between pharmacodynamics and pharmacokinetics to determine the rational daily administration frequency of Fufang Biejia Ruangan tablet. The results showed a good correlation between the inhibitory effect of Fufang Biejia Ruangan tablet-contained serum on HSC-T6 and the concentration of peoniflorin in blood. The two-time administration group showed higher pharmacologic and pharmacokinetic AUCs than one-time administration and three-time administration groups. In conclusion, Fufang Biejia Ruangan table is recommended to be taken twice a day for treating liver fibrosis in chronic hepatitis.

Mutation of the Strain Producing Higher Xylanase / 微生物学通报

A.niger M1, the initial strain, was treated by UV and a mutant with 30% higher xylanase activity was obtained. Zymogram for detecting xylanase showed there are three different xylanases in the mutant mature culture, while two xylanases in initial strain. After orthogonal experiment, the optimum fermentation conditions of the mutant were obtained as follows: concentration of the major carbon resource 4 %, ratio between bran and corncob 5:5, concentration of glucose 0.1%, concentration of ammonium oxalate as supplemental nitrogen resource 2.0%, the initial pH of liquid medium 5.0, 100mL/250mL flask.

Study on Lead Cation Biosorption of Saccharmyces cerevisiae 220 / 微生物学通报

Saccharmyces cerevisiae 220 has certain resistance to Pb2+ was found through the test of it's cultured on media containing lead cation. Sacchannyces cerevisiae 220 cultured was put into the media cotaining lead cation and it's biosorp-tion to lead cation was studied. The results show this strain has maximum biosorption ratio (96.6%) to 6mg/L lead cation, biosorption-equilibrilium period is 25-30min, biosorption kinitics equation is q-26.318C/ (1 + 0.437C) . Acetic acid is benefit to de-biosorption, glucose and KH2PO4 can improve biosorption ratio to lead cation.