Comparative analysis morphology, anatomical structure and transcriptional regulatory network of chlorophyll biosynthesis in Oryza longistaminata, O. sativa and their F1 generation.

Oryza longistaminata, a perennial wild species, is widely distributed in the African continent. It has strong tolerance to biotic and abiotic stresses, and high biomass production on poor soils. Chlorophyll biosynthesis is important for photosynthesis in rice. However, the chlorophyll biosynthesis and related gene profiles of O. longistaminata and its descendants remained unclear. Here, the F1 generation of O. sativa and O. longistaminata were obtained. Then, the comparative analysis morphology, anatomical structure, and transcriptional regulatory networks of chlorophyll biosynthesis were detected and analyzed. Results showed that the F1 generation has obvious long awn, similar with that of the male parent. The purple color of the long awn is different from that of the male parent. Microstructural results showed that the flag leaves of F1 have large mesophyll cell gaps in the upper- and lower-positions, small mesophyll cell gaps in the middle position, and more chloroplasts. Increased chlorophyll content was also observed in the F1 generation. In the lower-position flag leaves, the total chlorophyll contents of F1 were 1.55 and 1.5 times those of O. sativa and O. longistaminata, respectively. POR, MgCH and HEMA1 showed higher expression levels than the other related genes selected in the chlorophyll biosynthesis pathway. The HEMA1 expression level in the middle-position flag leaves of O. longistaminata was the highest, and it was 2.83 and 2.51 times that of O. sativa and F1, respectively. The expression level of DVR gene in lower-position flag leaves of F1 were 93.16% and 95.06% lower than those of O. sativa and O. longistaminata, respectively. This study provided a potential reference for studying the photosynthesis and heterosis utilization of O. longistaminata.

Resveratrol inhibits LPS-induced inflammation through suppressing the signaling cascades of TLR4-NF-κB/MAPKs/IRF3.

Resveratrol (Res) is a natural compound that possesses anti-inflammatory properties. However, the protective molecular mechanisms of Res against lipopolysaccharide (LPS)-induced inflammation have not been fully studied. In the present study, RAW264.7 cells were stimulated with LPS in the presence or absence of Res, and the subsequent modifications to the LPS-induced signaling pathways caused by Res treatment were examined. It was identified that Res decreased the mRNA levels of Toll-like receptor 4 (TLR4), myeloid differentiation primary response protein MyD88, TIR domain-containing adapter molecule 2, which suggested that Res may inhibit the activation of the TLR4 signaling pathway. It suppressed the expression levels of total and phosphorylated TLR4, NF-κB inhibitor, p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase, extracellular signal-regulated kinase 1/2 and interferon (IFN) regulatory factor 3 (IRF3) proteins. Following treatment with Res or specific inhibitors, the production of pro-inflammatory mediators including tumor necrosis factor-α, interleukin (IL)-6, IL-8 and IFN-ß were decreased and the expression of anti-inflammatory mediator IL-10 was increased. These results suggested that Res may inhibit the signaling cascades of NF-κB, MAPKs and IRF3, which modulate pro-inflammatory cytokines. In conclusion, Res exhibited a therapeutic effect on LPS-induced inflammation through suppression of the TLR4-NF-κB/MAPKs/IRF3 signaling cascades.

Tannic Acid Accelerates Cutaneous Wound Healing in Rats Via Activation of the ERK 1/2 Signaling Pathways.

Objective: This study was aimed to evaluate the effect of tannic acid (TA), a natural plant polyphenol astringent, on wound healing in vitro and in vivo, and to elucidate the underlying molecular signaling pathway in the wound healing. Approach: Cutaneous skin wounds were created in rats and then treated until closure with purified TA, serum or tissue samples were collected to test the concentration of factors by enzyme-linked immunosorbent assay (ELISA), and the expression in gene or protein was measured by quantitative real-time polymerase chain reaction or Western blot. We explored the cell-/dose-specific responses of TA (0.1-0.4 µg/mL) on proliferation and gene and protein expression of fibroblast NIH 3T3 cells. Results: The wounds on rats treated by TA got healed faster than those in the untreated group. The histopathology study showed that TA accelerated re-epithelialization and increase in hair follicles could be detected. The levels of growth factors including basic fibroblast growth factor (bFGF), transforming growth factor-beta, and vascular endothelial growth factor in TA-treated groups were all increased, and the content of interleukin-1 (IL-1) and IL-6 was decreased significantly when compared with that of the untreated group. The NIH 3T3 cells grow faster in 6 h at concentration of 0.1 µg/mL, and the expression of bFGF in gene and protein was increased significantly in the 0.1 µg/mL TA group. Further study revealed that the protein levels of bFGF, extracellular signal regulated kinase (Erk) 1/2, and P-Erk 1/2 in Erk 1/2 pathway were increased after TA treatment. Innovation: The role of TA in wound healing efficacy is unclear; this study, therefore, assesses the effects of TA on wound healing in different periods and the underlying molecular mechanisms. Conclusion: These results suggested that TA could accelerate wound healing through modulation of inflammatory cytokines and growth factors and activate Erk 1/2 pathway. In conclusion, TA may be a potential agent in promoting wound healing.

Antiviral Effect of Resveratrol in Piglets Infected with Virulent Pseudorabies Virus.

Pseudorabies virus (PRV) is one of the most important pathogens of swine, resulting in devastating disease and economic losses worldwide. Nevertheless, there are currently no antiviral drugs available for PRV infection. Resveratrol (Res) was identified to exert its antiviral activity by inhibiting the PRV replication in preliminary investigations. In our previous study, we found that Res has anti-PRV activity in vitro. Here, we show that Res can effectively reduce the mortality and increase the growth performance of PRV-infected piglets. After Res treatment, the viral loads significantly (p < 0.001) decreased. Pathological symptoms, particularly inflammation in the brain caused by PRV infection, were significantly (p < 0.001) relieved by the effects of Res. In Res-treated groups, higher levels of cytokines in serum, including interferon gama, interleukin 12, tumor necrosis factor-alpha and interferon alpha were observed at 7 days post infection. These results indicated that Res possesses potent inhibitory activity against PRV-infection through inhibiting viral reproduction, alleviating PRV-induced inflammation and enhancing animal immunity, suggesting that Res is expected to be a new alternative control measure for PRV infection.

iTRAQ-based quantitative proteomic analysis reveals multiple effects of Emodin to Haemophilus parasuis.

Haemophilus parasuis, a symbiotic bacteria of upper respiratory tract of swine, is the etiological agent of Glässer's disease, which is characterized by fibrinous polyserositis. Emodin, exhibits antibacterial activity against H. parasuis, yet the action mode has not been fully understood. In present study, isobaric tag for relative and absolute quantification (iTRAQ) method was applied to analyze the global protein alteration of H. parasuis in response to 16µg/mL Emodin. In total, 338 proteins exhibiting significant differential expressions were identified. It was speculated that, through application of bioinformatics analysis to theses differentially expressed proteins, Emodin mainly inhibited some key proteins expression of ABC transport system, carbohydrate metabolism pathway and bacterial cell division by inhibiting the ribosome synthesis, resulting in the growth inhibition of H. parasuis. Remarkably, nine virulence-associated proteins were detected differently expressed, further experiments revealed that after treatment with Emodin, H. parasuis could be inhibited to adhere to and invade into porcine kidney epithelial cells (PK-15 line) and exhibited increased sensitivity to serum complement in a concentration-dependent manner. Phagocytosis assay showed Emodin also could enhance phagocytic activity of porcine alveolar macrophages PAM to H. parasuis. These results indicated that Emodin also can attenuate virulence of H. parasuis and reduce infection. BIOLOGICAL SIGNIFICANCE: The Glässer's disease caused by H. parasuis has become a typical bacterial disease and cause serious economic loss to the swine industry around the world. Antibiotics are extensively used to control the infection, but increasing antibiotic resistance has been a severe problem. Hence, novel treatment agents are needed. So far, few antibacterial agents were reported that could control H. parasuis infection. In the present study, the state-of-the-art quantitative proteomic technology was applied to uncover underlying action mechanism of Emodin. This study extends understanding of antibacterial effect of Emodin to H. parasuis at molecular level and provides useful information for further investigations. Moreover, our results provide theoretical foundation for the practical application of Emodin.

Extraction and antioxidant activity of flavonoids of Morus nigra.

Morus nigra has a long history of medicinal use in Chinese medicine, but the study on it is limited, the flavonoids are one of the main biological active substances. In this study, the Morus nigra flavonoids were extracted by ultrasonic and antioxidant activities both in vitro and in vivo were measured. The results showed that hydroxyl radicals clearance rate and superoxide radical anion clearance rate in vitro increased with the concentration of the total flavonoids in the range of 0-1.05 mg/mL and the maximum clearance rate was 80.33% and 87.69%, respectively. After mice were treated with flavonoids, the content of malonaldehyde (MDA) in serum and liver decreased; the activities of superoxide dismutase (SOD) in serum and liver, catalase (CAT) in liver and glutathione peroxidase (GSH-PX) in blood and liver increased; Langhans cells increased in spleen. These results revealed that the Morus nigra flavonoids possessed strong antioxidant activity.