Targeted expression of Vitreoscilla hemoglobin improves the production of tropane alkaloids in Hyoscyamus niger hairy roots.

Under hypoxic conditions, the expression of Vitreoscilla hemoglobin (VHb) in plants is proposed to increase the productivity of certain oxygen-requiring metabolic pathways by promoting the delivery of oxygen. Tropane alkaloids (TAs) are a class of important plant secondary metabolites with significant medicinal value; the final step in their biosynthesis requires oxygen. Whether heterologous expression of VHb, especially in different subcellular compartments, can accelerate the accumulation of TAs is not known. Herein, the effect of heterologous expression of VHb in different subcellular locations on the TA profile of H. niger hairy roots was investigated. The targeted expression of VHb in the plastids (using pVHb-RecA construct), led to the accumulation of 197.68 µg/g hyoscyamine in the transgenic H. niger hairy roots, which was 1.25-fold of the content present in the lines in which VHb expression was not targeted, and 3.66-fold of that present in the wild type (WT) lines. The content of scopolamine was increased by 2.20- and 4.70-fold in the pVHb-RecA transgenic lines compared to that in the VHb transgenic and WT lines. Our results demonstrate that VHb could stimulate the accumulation of TAs in the transgenic H. niger hairy roots. Quantitative RT-PCR analysis revealed that the expression of key genes involved in TA biosynthesis increased significantly in the VHb transgenic lines. We present the first description of a highly efficient strategy to increase TA content in H. niger. Moreover, our results also shed light on how the production of desired metabolites can be efficiently enhanced by using more accurate and appropriate genetic engineering strategies.

Efficacy of extracts of Celastrus orbiculatus in suppressing migration and invasion by inhibiting the EZH2/ROCK1 signaling pathway in human nasopharyngeal carcinoma.

Celastrus orbiculatus extract (COE) has been used in folk medicine in China for the treatment of a number of diseases. In the laboratory, COE exhibits a variety of anticancer functions, including inhibition of metastasis. However, the underlying molecular anti-metastatic mechanism in nasopharyngeal carcinoma (NPC) cells remains unclear. The aim of the present study was to determine whether the anti-metastatic effect of COE was involved in inhibiting migration and invasion of human NPC cells. In vitro, cell viability and apoptosis of 5-8F cells were analyzed using an MTS assay and flow cytometry, respectively. Invasion and migration of 5-8F cells were analyzed using a Transwell assay. Protein and mRNA expression levels of 5-8F cells were analyzed by western blot analysis and the reverse transcription-quantitative polymerase chain reaction, respectively. COE significantly decreased cell viability in 5-8F cells and inhibited enhancer of zeste homolog 2 (EZH2) and Rho-associated coiled coil-containing protein kinase 1 (ROCK1) expression at the mRNA and protein levels. Furthermore, COE decreased the migration and invasion of 5-8F cells in a dose-dependent manner. The results of the present study suggested that COE prevents migration and invasion by suppressing the EZH2/ROCK1 signaling pathway in NPC cells. On the basis of the results of the present study, COE may be a novel anticancer agent for the treatment of metastasis in NPC.

Stable Internal Reference Genes for Normalizing Real-Time Quantitative PCR in Baphicacanthus cusia under Hormonal Stimuli and UV Irradiation, and in Different Plant Organs.

Baphicacanthus cusia (Nees) Bremek, the plant source for many kinds of drugs in traditional Chinese medicine, is widely distributed in South China, especially in Fujian. Recent studies about B. cusia mainly focus on its chemical composition and pharmacological effects, but further analysis of the plant's gene functions and expression is required to better understand the synthesis of its effective compounds. Real-time quantitative polymerase chain reaction (RT-qPCR) is a powerful method for gene expression analysis. It is necessary to select a suitable reference gene for expression normalization to ensure the accuracy of RT-qPCR results. Ten candidate reference genes were selected from the transcriptome datasets of B. cusia in this study, and the expression stability was assessed across 60 samples representing different tissues and organs under various conditions, including ultraviolet (UV) irradiation, hormonal stimuli (jasmonic acid methyl ester and abscisic acid), and in different plant organs. By employing different algorithms, such as geNorm, NormFinder, and BestKeeper, which are complementary approaches based on different statistical procedures, 18S rRNA was found to be the most stable gene under UV irradiation and hormonal stimuli, whereas ubiquitin-conjugating enzyme E2 was the best suitable gene for different plant organs. This novel study aimed to screen for suitable reference genes and corresponding primer pairs specifically designed for gene expression studies in B. cusia, in particular for RT-qPCR analyses.

Achyranthes bidentate saponins protect rat articular chondrocytes against interleukin-1ß-induced inflammation and apoptosis in vitro.

Achyranthes bidentate Blume (Niuxi) is often employed for treatment of arthritis in Traditional Chinese Medicine and possesses anti-inflammatory properties. Phytochemical and pharmacological studies proved the oleanane-type saponins to be the main bioactive principles. In the present study, protective effects of A. bidentata saponins (ABS) on inflammation and apoptosis in interleukine-1ß (IL-1ß)-induced chondrocytes were investigated. Rat chondrocytes were pretreated with ABS at 3 µg/mL, 10 µg/mL, and 30 µg/mL, and subsequently stimulated with IL-1ß (10 ng/mL). Methylthiazolyldiphenyl-tetrazolium bromide assay and annexin V/propidium iodide dual staining demonstrated that ABS could protect IL-1ß-induced chondrocyte injury. ABS suppressed IL-1ß-induced apoptosis by suppressing the activation of caspase-3, inhibiting levels of proapoptotic proteins Bax and Bad, decreasing p53 protein phosphorylation, and promoting the expression of antiapoptotic protein Bcl-xL and proliferating cell nuclear antigen. IL-1ß-induced inflammation and matrix degradation were also alleviated by ABS through the downregulation of the expressions of matrix metalloproteinases 3 and 9 and cyclooxygenase-2. Moreover, ABS inhibited IL-1ß-induced nuclear factor κB activation in rat chondrocytes. We demonstrated, for the first time, the protective effects of ABS on IL-1ß-stimulated chondrocytes and their molecular mechanisms. Thus, it is suggested that ABS might be a potential drug in the treatment of osteoarthritis.