Comparative Analysis of Water-Soluble Polysaccharides from Dendrobium Second Love 'Tokimeki' and Dendrobium nobile in Structure, Antioxidant, and Anti-Tumor Activity In Vitro.

With potential anti-tumor and antioxidant properties, the polysaccharide content of D. nobile is relatively lower than that of the other medicinal Dendrobium. To find high-content polysaccharide resources, the polysaccharide (DHPP-Ⅰs) was prepared from D. Second Love 'Tokimeki' (a D. nobile hybrid) and compared with DNPP-Ⅰs from D. nobile. DHPP-Is (Mn 31.09 kDa) and DNPP-Is (Mn 46.65 kDa) were found to be O-acetylated glucomannans (-Glcp-(1,4) and O-acetylated-D-Manp-(1,4) backbones), analogous to other Dendrobium polysaccharides. DHPP-Ⅰs had higher glucose content (31.1%) and a lower degree (0.16) of acetylation than DNPP-Ⅰs (15.8%, 0.28). Meanwhile, DHPP-Ⅰs and DNPP-Ⅰs had the same ability in the radical scavenging assay, which was milder than the control of Vc. Both DHPP-Is and DNPP-Is inhibited SPC-A-1 cell proliferation in vitro, with obvious differences in dose concentrations (0.5-2.0 mg/mL) and treatment times (24-72 h). Therefore, the antioxidant activity of DHPP-Ⅰs and DNPP-Ⅰs is not associated with distinction in anti-proliferative activity. As a glucomannan derived from non-medicinal Dendrobium, DHPP-Ⅰs has similar bioactivity to other medicinal Dendrobium, and this could serve as a starting point for studying the conformational-bioactivity relationship of Dendrobium polysaccharides.

Structural characterization and antitumor activity of a polysaccharide from Dendrobium wardianum.

Through hot water extraction, protein removal and chromatographic purification, DWPP-Is was found to be the major polysaccharide present in the stem of D. wardianum. The Mn and Mw of DWPP-Is were 29.0 kDa and 98.6 kDa, respectively. Furthermore, mannose and glucose were found to be the most abundant monosaccharides in DWPP-Is. Their backbones consist of (1 â†’ 4)-ß-d-Glcp and O-acetylated (1 â†’ 4)-ß-d-Manp, which are similar to the structures of other anti-tumour Dendrobium polysaccharides. The inhibition rate of DWPP-Is treatment on SPC-A-1 cells (2 mg/mL, 72 h) reached 56.0%. Intragastric administration of DWPP-Is on A549 tumour-bearing KM mice (10 mg/mL, 0.2 mL) exhibited similar inhibition ratios to that of erlotinib hydrochloride (2 mg/mL). Moreover, the highest inhibition was observed in P-CK treatment combined with DWPP-Is, reaching an inhibition rate of 23.4%. These results suggest that DWPP-Is has the potential to be a functional agent for lung cancer prevention.

Erratum: MicroRNA-26b suppresses autophagy in breast cancer cells by targeting DRAM1 mRNA, and is downregulated by irradiation.

[This corrects the article DOI: 10.3892/ol.2017.7452.].

Proteomic Analysis of the Early Development of the Phalaenopsis amabilis Flower Bud under Low Temperature Induction Using the iTRAQ/MRM Approach.

Phalaenopsis amabilis, one of the most important plants in the international flower market due to its graceful shape and colorful flowers, is an orchid that undergoes vernalization and requires low-temperature treatment for flowering. There have been few reports on the proteomics of the development of flower buds. In this study, isobaric tags for relative and absolute quantification (iTRAQ) were used to identify 5064 differentially expressed proteins in P. amabilis under low-temperature treatment; of these, 42 were associated with early floral induction, and 18 were verified by mass spectrometry multi-reaction monitoring (MRM). The data are available via ProteomeXchange under identifier PXD013908. Among the proteins associated with the vernalization pathway, PEQU_11434 (glycine-rich RNA-binding protein GRP1A-like) and PEQU_19304 (FT, VRN3 homolog) were verified by MRM, and some other important proteins related to vernalization and photoperiod pathway that were detected by iTRAQ but not successfully verified by MRM, such as PEQU_11045 (UDP-N-acetylglucosamine diphosphorylase), phytochromes A (PEQU_13449, PEQU_35378), B (PEQU_09249), and C (PEQU_41401). Our data revealed a regulation network of the early development of flower buds in P. amabilis under low temperature induction.

Proteomic and Biochemical Changes during Senescence of Phalaenopsis 'Red Dragon' Petals.

Phalaenopsis flowers are some of the most popular ornamental flowers in the world. For most ornamental plants, petal longevity determines postharvest quality and garden performance. Therefore, it is important to have insight into the senescence mechanism of Phalaenopsis. In the present study, a proteomic approach combined with ultrastructural observation and activity analysis of antioxidant enzymes was used to profile the molecular and biochemical changes during pollination-induced petal senescence in Phalaenopsis “Red Dragon”. Petals appeared to be visibly wilting at 24 h after pollination, accompanied by the mass degradation of macromolecules and organelles during senescence. In addition, 48 protein spots with significant differences in abundance were found by two-dimensional electrophoresis (2-DE) and subjected to matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF/TOF-MS). There were 42 protein spots successfully identified and homologous to known functional protein species involved in key biological processes, including antioxidant pathways, stress response, protein metabolism, cell wall component metabolism, energy metabolism, cell structure, and signal transduction. The activity of all reactive oxygen species (ROS)-scavenging enzymes was increased, keeping the content of ROS at a low level at the early stage of senescence. These results suggest that two processes, a counteraction against increased levels of ROS and the degradation of cellular constituents for maintaining nutrient recycling, are activated during pollination-induced petal senescence in Phalaenopsis. The information provides a basis for understanding the mechanism regulating petal senescence and prolonging the florescence of Phalaenopsis.

MicroRNA-26b suppresses autophagy in breast cancer cells by targeting DRAM1 mRNA, and is downregulated by irradiation.

MicroRNAs (miRs) are small RNAs that do not code for proteins, but instead decrease the stability and suppress the translation of target mRNAs by binding with complementary sequences in their 3'-untranslated regions (3'-UTRs). In the present study, it is reported that breast cancer tumor tissue, as well as irradiated MCF7 breast cancer cells, exhibit decreased levels of miR-26b expression compared with normal breast tissue and MCF7 cells without exposure to radiation. Additionally, a luciferase reporter assay was used to demonstrate that miR-26b directly targetsDNA damage-regulated autophagy modulator 1 (DRAM1). MCF7 cells that were transfected with an miR-26b mimicexhibited the downregulated expression of DRAM1 protein and a reduced level of irradiation-induced autophagy. Inhibiting miR-26b resulted in the upregulation of DRAM1 and increased levels of irradiation-induced autophagy in MCF7 cells. These results suggest that therapeutic strategies to target miR-26b may increase the efficacy of certain types of cancer therapy.

Caveolin-1 Mediates Low-Intensity Ultrasound-Induced Apoptosis via Downregulation of Signal Transducer and Activator of Transcription 3 Phosphorylation in Laryngeal Carcinoma Cells.

Low-intensity ultrasound therapy has been found to be a potential tool in the management of malignant tumors in recent years. However, the molecular mechanism underlying low-intensity ultrasound-induced apoptosis is still not clear. In this study, we investigated the effects of low-intensity ultrasound-induced apoptosis in HEp-2 cells. We found that low-intensity ultrasound significantly induced apoptosis, and the expression level of caveolin-1 (Cav-1) was dramatically increased after ultrasound treatment of HEp-2 cells. After inhibiting the expression level of Cav-1 using siRNA transfection, we found that the cellular apoptosis induced by low-intensity ultrasound was significantly suppressed. In addition, inhibition of Cav-1 expression promoted phosphorylation of signal transducer and activator of transcription 3 (STAT3), suggesting that the STAT3 signaling pathway was involved in low-intensity ultrasound-induced apoptosis via Cav-1 regulation. Our results indicate that Cav-1/STAT3 signaling pathway may mediate low-intensity ultrasound-induced apoptosis, and this technology could potentially be used clinically for the treatment of cancers.

[Research and realization of signal processing algorithms based on FPGA in digital ophthalmic ultrasonography imaging].

OBJECTIVE: To design and improve signal processing algorithms of ophthalmic ultrasonography based on FPGA. METHODS: Achieved three signal processing modules: full parallel distributed dynamic filter, digital quadrature demodulation, logarithmic compression, using Verilog HDL hardware language in Quartus II. RESULTS: Compared to the original system, the hardware cost is reduced, the whole image shows clearer and more information of the deep eyeball contained in the image, the depth of detection increases from 5 cm to 6 cm. CONCLUSION: The new algorithms meet the design requirements and achieve the system's optimization that they can effectively improve the image quality of existing equipment.

Composition analysis and anti-proliferation activity of polysaccharides from Dendrobium chrysotoxum.

Water-soluble polysaccharides (DCCP, DCPP) were extracted from the stems of Dendrobium chrysotoxum using boiling water and ultrasound. DCPP were successively purified by chromatography on DEAE-Cellulose-52 and Sephadex G-200 column, giving three major polysaccharide fractions termed DCPP-I, DCPP-I-a and DCPP-II. Among these fractions, DCPP-I-a exhibited the highest abundance (79.5%). The number-average molecular weight and weight-average molecular weight of DCPP-I-a were 67 kDa and 122 kDa, respectively. Monosaccharide components analysis indicated that DCPP-I-a were composed of xylose, glucose, galactose in a molar ratio of 1.44:6.93:12.79. Infrared spectra (IR) and (1)H NMR showed that DCPP-I-a was composed of a ß-D pyran ring with a ß-configuration. The evaluation of anti-proliferation activity suggested that DCPP-I-a and DCPP-II had a higher inhibitory effect on the SPC-A-1 cells than DCCP as determined with in vitro anti-proliferation test.

Transcriptional Regulations on the Low-Temperature-Induced Floral Transition in an Orchidaceae Species, Dendrobium nobile: An Expressed Sequence Tags Analysis.

Vernalization-induced flowering is a cold-relevant adaptation in many species, but little is known about the genetic basis behind in Orchidaceae species. Here, we reported a collection of 15017 expressed sequence tags (ESTs) from the vernalized axillary buds of an Orchidaceae species, Dendrobium nobile, which were assembled for 9616 unique gene clusters. Functional enrichment analysis showed that genes in relation to the responses to stresses, especially in the form of low temperatures, and those involving in protein biosynthesis and chromatin assembly were significantly overrepresented during 40 days of vernalization. Additionally, a total of 59 putative flowering-relevant genes were recognized, including those homologous to known key players in vernalization pathways in temperate cereals or Arabidopsis, such as cereal VRN1, FT/VRN3, and Arabidopsis AGL19. Results from this study suggest that the networks regulating vernalization-induced floral transition are conserved, but just in a part, in D. nobile, temperate cereals, and Arabidopsis.

Isolation and structural characterization of a neutral polysaccharide from the stems of Dendrobium densiflorum.

A novel neutral heteropolysaccharide (DDP-1-D) was purified from hot water extracts of dried stem of Dendrobium densiflorum by DEAE-52 and Sephacryl S-200 High-Resolution Chromatography. The heteropolysaccharide had an average molecular weight about 9440 Da. It was composed mainly of glucose and mannose in the ratio of 3.01:1. Structural features of DDP-1-D were elucidated by a combination of chemical and instrumental techniques, including FT-IR, GC-MS, periodate oxidation-Smith degradation, (1)H and (13)C NMR spectroscopies (including COSY, TOCSY, HSQC, and HMBC spectra). The results indicated that DDP-1-D is a mannoglucan and has a backbone consisting of (1→4)-linked α-D-Glcp, (1→6)-linked α-D-Glcp, (1→2)-linked α-D-Manp and (1→4)-linked ß-Manp. This is the first study to provide clear evidence for the structure of the polysaccharide in D. densiflorum.

[Recovery of bromeliad photosynthesis after exposure to elevated CO2].

After exposed to elevated CO2 [T1: (600 +/- 40) micromol x mol(-1) and T2: (900 +/- 40) micromol x mol(-1)] for 150 days, Guzmania 'Luna' and Guzmania 'Denise' were transferred to ambient CO2 for 30 days to investigate the recovery of their photosynthesis and their key photosynthetic enzyme activities. The results showed that compared with that in CK, the net photosynthetic rate (Pn) of Guzmania 'Luna' in treatments T1 and T2 was decreased by 7.41% and 13.33%, respectively. The Pn of Guzmania 'Denise' in T1 was approached to CK, and that in T2 was higher than CK. After 30 days recovery, the accumulation of soluble sugar and starch in test bromeliads leaves decreased obviously, with the contents being close to those of CK. The rubisco and glycolate oxidase activities in treatments T1 and T2 had a decreased difference with CK, but were still lower than those of CK.

[The influence of abscisic acid treatment on desiccation tolerance in Dendrobium candidum protocorm-like bodies].

Effect of ABA on desiccation tolerance in the protocorm-like bodies (PLBs) of D. candidum was studied. The best result was obtained while ABA precultured at 5 micromol/L for 24 h (Fig.2). PLBs vitality rate was 10 times of the control after 2 h desiccation (Table 1). Detection of cytoplasmic osmoticums showed that ABA preculture could not induce the accumulations of soluble sugar, proline, etc (Tables 3, 4 and 7). But the content of soluble polysaccharide rose conspicuously (Table 5). So we think that the accumulation of soluble polysaccharide may play an important role in desiccation tolerance induced by ABA preculture.