Cloning and expression of the key enzyme hyoscyamine 6 beta-hydroxylase gene (DaH6H) in scopolamine biosynthesis of Datura arborea / 药学学报

Hyoscyamine 6 beta-hydroxylase (H6H) is the last rate-limiting enzyme directly catalyzing the formation of scopolamine in tropane alkaloids (TAs) biosynthesis pathway. It is the primary target gene in the genetic modification of TAs metabolic pathway. Full-length cDNA and gDNA sequences of a novel H6H gene were cloned from Datura arborea (DaH6H, GenBank accession numbers for cDNA and gDNA are KR006981 and KR006983, respectively). Nucleotide sequence analysis reveals an open reading frame of 1375 bp encoding 347 amino acids in the cDNA of DaH6H, while the gDNA of DaH6H contains four exons and three introns, with the highest similarity to the gDNA of H6H from D. stramonium. DaH6H also exhibited the most identity of 90.5% with DsH6H in amino acids and harbored conserved 2-oxoglutarate binding motif and two iron binding motifs. The expression level of DaH6H was highest in the mature leaf, followed by the secondary root, and with no expression in the primary root based on qPCR analysis. Its expression was inhibited by MeJA. DaH6H was expressed in E. coli and a 39 kD recombinant protein was detected in SDS-PAGE. Comparison of the contents of scopolamine and hyoscyamine in various TAs-producing plants revealed that D. arborea was one of the rare scopolamine predominant plants. Cloning of DaH6H gene will allow more research in the molecular regulatory mechanism of TAs biosynthesis in distinct plants and provide a new candidate gene for scopolamine metabolic engineering.

Serumimmunological study of moxibustion on helicobacter pylori gastritis in rats / 中国针灸

<p><b>OBJECTIVE</b>To explore the immune mechanism of moxibustion on protecting gastric mucosa injury.</p><p><b>METHODS</b>Forty healthy SD rats were randomly divided into four groups: a blank group, a model group, a moxibustion acupoint group and a moxibustion non-acupoint group, 10 rats in each one. Eight days before model establishment, moxibustion at "Zusanli" (ST 36), "Zhongwan" (CV 12), "Guanyuan" (CV 4), "Pishu" (BL 20) and "Weishu" (BL 21) was applied in the moxibustion acupoint group while these acupoints' controlled points were selected in the moxibustion non-acupoint group, and no treatment was given in the model group, once a day in three groups for continuous 16 days. The helicobacter pylori (Hp) model was established by intragastric administration of Hp. HE staining microscopic examination was used to observe inflammation severity in gastric mucosa, and enzyme-linked immunosorbent assay (ELISA) was adapted to measure content of heat shock protein (HSP) 72, TNF-alpha and IL-1beta, and real-time quantitative PCR was used to measure the expression of TLR2 mRNA, TLR4 mRNA, CD14 mRNA and MyD88 mRNA in peripheral blood mononuclear cells, and western blot method was used to measure content of NFkappaB and IkappaBalpha in peripheral blood mononuclear cells.</p><p><b>RESULTS</b>Compared with the blank group, the expression of HP could be seen in the smear of gastric mucosa by Gram's staining in the model group; the inflammation severity score was obviously increased as well as content of serum HSP 72 and TNF-alpha and IL-1beta in gastric tissue; and expression of TLR2, 4 mRNA, CD14 mRNA, MyD88 mRNA, NFkappaB was increased (P < 0.01), but the expression of IkappaBalpha was reduced (P < 0.05). After the moxibustion, the inflammation severity score was reduced in the moxibustion acupoint group, and the content of serum HSP 72 was increased, and the expression of TNF-alpha and IL-1beta in gastric tissue and expression of TLR2 mRNA, TLR4 mRNA, CD14 mRNA, MyD88 mRNA and NFkappaB were reduced (P < 0.01), but the expression of IkappaBalpha was increased (P < 0.05). The differences between the moxibustion non-acupoint group and the model group were not significant (P > 0.05).</p><p><b>CONCLUSION</b>The pretreatment of moxibustion at acupoints could induce the over expression of serum HSP 72. By combining TLR 2 and 4 receptors to trigger receptor signal transduction pathways, the releases of downstream signal substances are regulated; as a result, the releases of related immune substances are regulated to relieve the gastric mucosa injury of rats with HP gastritis.</p>