Cloning and functional analysis of flavanone 3-hydroxylase gene in Rhododendron hybridum Hort / 生物工程学报

Flavanone 3-hydroxylase (F3H) is a key enzyme in the synthesis of phycocyanidins. In this experiment, the petals of red Rhododendron hybridum Hort. at different developmental stages were used as experimental materials. The R. hybridum flavanone 3-hydroxylase (RhF3H) gene was cloned using reverse transcription PCR (RT-PCR) and rapid-amplification of cDNA ends (RACE) techniques, and bioinformatics analyses were performed. Petal RhF3H gene expression at different developmental stages were analyzed by using quantitative real-time polymerase chain reaction (qRT-PCR). A pET-28a-RhF3H prokaryotic expression vector was constructed for the preparation and purification of RhF3H protein. A pCAMBIA1302-RhF3H overexpression vector was constructed for genetic transformation in Arabidopsis thaliana by Agrobacterium-mediated method. The results showed that the R. hybridum Hort. RhF3H gene is 1 245 bp long, with an open reading frame of 1 092 bp, encoding 363 amino acids. It contains a Fe2+ binding motif and a 2-ketoglutarate binding motif of the dioxygenase superfamily. Phylogenetic analysis showed that the R. hybridum RhF3H protein is most closely related to the Vaccinium corymbosum F3H protein. qRT-PCR analysis showed that the expression level of the red R. hybridum RhF3H gene tended to increase and then decrease in the petals at different developmental stages, with the highest expression at middle opening stage. The results of the prokaryotic expression showed that the size of the induced protein of the constructed prokaryotic expression vector pET-28a-RhF3H was about 40 kDa, which was similar to the theoretical value. Transgenic RhF3H Arabidopsis thaliana plants were successfully obtained, and PCR identification and β-glucuronidase (GUS) staining demonstrated that the RhF3H gene was integrated into the genome of A. thaliana plants. qRT-PCR, total flavonoid and anthocyanin contentanalysis showed that RhF3H was significantly higher expressed in the transgenic A. thaliana relative to that of the wild type, and its total flavonoid and anthocyanin content were significantly increased. This study provides a theoretical basis for investigating the function of RhF3H gene, as well as for studying the molecular mechanism of flower color in R. simsiib Planch.

Anti-obesity effect of combined treatment of hyperforin and amlexanox on ob/ob mice / 中华内分泌代谢杂志

Objective:To investigate the effect of combined treatment of hyperforin(HPF) and amlexanox(AM) on obesity and metabolic disorders.Methods:ob/ob mice were used as an obese mice model and treated with HPF alone(2.5 mg/kg intraperitoneal injection) or combined with AM(50 mg/kg, gavage administration) for 4 weeks. Their body weight and food intake were monitored, glucose tolerance test and insulin tolerance test were performed, serum alanine aminotransferase(ALT) and aspartate aminotransferase(AST) levels were detected. Nuclear magnetic resonance was used to detect the body composition and metabolic cage was used to detect the energy consumption. After sampling, HE staining was used to observed the pathological change of fat and liver tissues, Western blotting and enzyme-linked immunosorbent assay(ELISA) were used to detect the cyclic adenosine monophosphate(cAMP)-protein kinase A(PKA) signaling pathway.Results:Compared to the vehicle-treated mice(54.07 g), HPF-treated mice showed attenuated body weight gain(51.33 g, P=0.042) and reduced total fat mass( P=0.011); while administration of HPF in combination with AM(HPF/AM) further reduced the body weight(47.61 g, P=0.041). HE staining analysis showed that HPF alone or HPF/AM treatment both decreased the diameters of adipocytes and infiltration of white fat( P=0.014, P=0.032) in brown adipose tissues, which resulted in a trend of browning. However, HPF/AM-treatment didn′t further diminish adipocytes or reduce lipid accumulation in brown adipose tissues compared to HPF-treated mice. In addition, the basal oxygen consumption rate(VO 2, P<0.001) and(VCO 2, P=0.002) of HPF-treated mice were mainly elevated in the light phase relative to that of control mice; while HPF/AM-treatment further promote the energy consumption both in the dark phase and light phase. Notably, cAMP-PKA signaling pathway was obviously activated under HPF/AM-treatment in inguinal white adipose tissue. Moreover, HPF/AM-treatment showed beneficial effects on glucose metabolism and fatty liver, as indicated by improved insulin resistance, reduced liver steatosis( P=0.049) and the serum ALT levels( P=0.008). Conclusion:Combined administration of HPF and AM is an effective strategy in the treatment of obesity, improvement of metabolic disorders and alleviation of catecholamine resistance.

Cloning and functional analysis of the phenylalaninammo-nialyase gene from Rhododendron fortunei / 生物工程学报

Phenylalaninammo-nialyase (PAL) is a key enzyme in the synthesis of methyl benzoate - a plant aroma compound. In order to understand the function of this enzyme in the formation of fragrance in the scented Rhododendron species-Rhododendron fortunei, we cloned a gene encoding this enzyme and subsequently examined the gene expression patterns and the profile of enzyme activity during development in various tissues. The full length of RhPAL gene was cloned by reverse transcription-PCR (RT-PCR) and rapid amplification of cDNA ends (RACE) techniques. The expression levels of RhPAL gene were measured by real-time quantitative reverse transcription PCR (qRT-PCR) and the amount of phenylalanine and cinnamic acid were assayed with LC-MS. The results showed that the ORF sequence of RhPAL gene amplified from the cDNA templates of flower buds had 2 145 bp, encoding 715 amino acids, and shared 90% homology to the PAL amino acid sequences from other species. qRT-PCR analysis showed that the expression of RhPAL in petals during flowering kept in rising even until the flowers wilted. The expression of RhPAL in pistil was much higher than that in stamen, while the expression in the younger leaves was higher than in old leaves. However, the expression level was relatively lower in petal and stamen compared to that in leaves. We also measured the PAL activity by Enzyme-linked immuno sorbent assay in the petals of flowers at different flowering stages. The results showed that PAL activity reached the highest at the bud stage and then decreased gradually to the lowest when the flowers wilted, which followed a similar trend in the emission of the flower fragrance. The phenylalanine and cinnamic acid contents measured by LC-MS were highly correlated to the expression level of RhPAL in various tissues and at different flowering stages, implying that RhPAL plays an important role in the formation of the flower fragrance. This work may facilitate the breeding and improvement of new fragrant Rhododendron cultivars.

Effect of Nicorandil on unstable angina patients with persistent weak positive for troponin-I / 心血管康复医学杂志

Objective:To discuss effect of nicorandil on unstable angina patients With persistent Weakly positive for troponin I (TnI).Methods:A total of 111 unstable angina patients With persistent Weakly positive for TnI Were randomly divided into control group (received routine treatment,55 cases) and intervention group (received nic-orandil 5mg,3 times/d based on routine treatment,56 cases).The relief of chest pain in one Week,the recurrent hospitalization for chest pain aggravation in 3 months and the cardiac mortality rate in one year betWeen tWo groups Were observed in tWo groups. Results:Compared With control group,the relief of angina pectoris in one Week (63.6% vs. 91.1%,χ2=11.97,P=0.0005)significantly increased,re-hospitalization for chest pain aggravation in three months (56.4% vs.19.6%,χ2=15.91,P=0.0001)significantly decreased in intervention group;but cardiac mortality rate during one year betWeen tWo groups Was no significant difference (5.5% vs. 8.9%,χ2=0.50,P=0.4792).Conclusion:Nicorandil can significantly reduce the unstable angina and re-hospitalization for chest pain aggravation in patients With persistent Weakly positive for TnI,but there Was no significant difference in reducing mortality Within one year betWeen tWo groups.