Research progress on triterpenoids of Betula plants / 药学学报

The secondary metabolites of plants are important sources of natural drugs. Betula plants have abundant pharmacological value, complex mechanism and wide applications, which are closely related to the triterpenoids of theirs. Triterpenoids in Betula species are mainly divided into dammarane-type, ocotillol-type, oleanane-type, lupane-type and cycloaltunane-type. The extracts of Betula species have varieties of activities such as anti-tumor, anti-inflammatory, anti-oxidant, anti-bacterial, etc. And the biosynthetic pathways of triterpenoids after 2,3-oxidosqualene are split into four branches of dammarenediol-II, lupeol, cycloartenol and amyrin according to the different oxidosqualene cyclases. This review summarizes the chemical constituents, pharmacological activities and biosynthetic pathways of triterpenoids in Betula plants. It provides a reference for the research and development of new drugs and the production of these triterpenoids in microbial cell factories by synthetic biology methods.

Effect of TEB-415, a Derivative of Imatinib, on Multiple Myeloma / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the growth inhibitory effect of Imatinib derivative TEB-415 on various multiple myeloma (MM) cell lines, such as U226, H929, RPMI8226, MM1R and MM1S.</p><p><b>METHODS</b>TEB-415, a derivative of Imatinib was synthesized by modifying the chemical structure of Imatinib. MM cell lines (U226, H929, RPMI8226, MM1R and MM1S) were treated with TEB-415, Imatini and Bortezomib of various concentrations. Cells were grown for 72 hours and the growth rate was measured by CCK-8 method, cell morphology was observed and the IC50 was calculated.</p><p><b>RESULTS</b>TEB-415 could inhibit H929 and RPMI8226 growth significantly. When the concentration of TEB-415 was <0.1 nmol/L, >50% H929 cells died. The IC50 of Imatinib was 0.123 mol/L while the IC50 of Bortezomib was 0.03 nmol/L. In RPMI8226 cell line, when the concentration of TEB-415 was 11.9 mol/L, more than 50% of cells died. In contrast, when RPMI8266 were treated with Imatinib of the concentration of 12.8 mol/L, cells grew normally.</p><p><b>CONCLUSION</b>In comparison to Imatinib, TEB-415, a derivative of Imatinib, can kill H929 MM cells much effectively, its effecacy is only inferior to Bortezomib. RPMI8226, an MM cell line is insensitive to Imatinib, but still sensitive to TEB-415 and its growth can be inhibited by TEB-415.</p>

An improved method for generating integration-free human induced pluripotent stem cells / 中国实验血液学杂志

The genome instability and tumorigenicity of induced pluripotent stem cells (iPSC) hinder their great potentials for clinical application. Using episomal vectors to generate iPSC is the best way to solve safety issues at present. This method is simple and the exogenous gene was not integrated into the host genome. However, the reprogramming efficiency for this method is very low and thus limits its usage. This study was purposed to improve episomal method for generating induced pluripotent stem cells from cord blood mononuclear cells (CB MNC), to establish integration-free iPSC technology system, and to lay the foundation for individualized iPSC for future clinical uses. To improve the reprogramming efficiency for iPSC, episomal method was used at various combinations of episomal vectors, pre-stimulating culture mediums and oxygen condition were tested to optimize the method. The results showed that using erythroid culture medium for culturing 8 days, transfecting with episomal vectors with SFFV (spleen focus forming virus) promoter under the hypoxic condition (3%), CB MNC could be mostly efficiently reprogrammed with the efficiency 0.12%. Furthermore, the results showed that erythroblasts (CD36(+)CD71(+)CD235a(low)) were the cells that are reprogrammed with high efficiency after culture for 8 days. It is concluded that a highly efficient and safe method for generation of integration-free iPSC is successfully established, which is useable in clinical study.

Efficient reprogramming of human cord blood CD34(+) cells for formation of induced pluripotent stem cells with non-integrating plasmid system / 中国实验血液学杂志

This study was to establish the episomal vector reprogramming method to reprogram iPSC from human cord blood (CB) CD34(+) cells. The non-integrating plasmids of pEB-C5 and pEB-Tg were transfected into short-term cultured CB CD34(+) cells by using the nucleofector, so as to demonstrate efficient reprogramming of CB CD34(+) cells. Within 14 days of one-time transfection by two plasmids together, up to 200 iPSC-like colonies per 2 million transfected CB CD34(+) cells were generated. The results showed that the pluripotency of iPSC-derived CB CD34(+) cells was similar to that of hESC and the karyotypes of iPSC were normal. In addition, no vector integration was found in iPSC of 9th and 10th passages. Furthermore, hiPSC formed teratoma with three embryonic germ layers. It is concluded that the integration-free method to generate human iPSC from CB CD34(+) cells is reliable and can provide new ways for both research and future clinical applications.

Detection of beef contaminated by bovine central nervous system tissue by enzyme immunoassay / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study influencing factors of detection of bovine central nervous system (CNS) tissue contaminated beef by enzyme immunoassay (EIA), and the method was applied to the detection of imported beef and domestic beef of China.</p><p><b>METHODS</b>Raw beef homogenates containing different concentrations of raw CNS tissue and the same samples which were heated were detected after different time by RIDASCREEN(r) Risk Material 10/5 and RIDASCREEN(r) Probennahme- zubehor Sampling tools kits. PBS suspension and sample dilution buffer (SDB) suspension of bovine brain tissue with the same concentration of the standard were detected. Beef from USA and domestic market of China were then detected by the kits.</p><p><b>RESULTS</b>The kits could detect both raw and heated CNS tissue in the products with high sensitivity. The absorbance values (AV) increased with the concentrations of CNS in samples. Heating and increasing of time could decrease the absorbance values of the samples which contain CNS tissue. The AV of the PBS suspension of bovine brain tissue was higher than the SDB suspension and the AV of both were higher than the AV of standard of the same concentration. No CNS tissue was detected from all imported beef. No CNS tissue was detected in all samples from domestic market of China except for foxtail.</p><p><b>CONCLUSION</b>The EIA method has high sensitivity for detection of bovine CNS tissue contaminated beef with the glial fibrillary acidic protein (GFAP) as accurate target substance. Heating and increasing of time can lead to decreasing of the AV of samples. Improper slaughter process can lead to contamination of bovine products by bovine CNS tissue.</p>