Fusobacterium necrophorum Promotes Apoptosis and Inflammatory Cytokine Production Through the Activation of NF-κB and Death Receptor Signaling Pathways.

Fusobacterium necrophorum can cause liver abscess, foot rot in ruminants, and Lemire syndrome in humans, Also, its virulence factors can induce the apoptosis of macrophages and neutrophils. However, the detailed mechanism has not been fully clarified. This study investigated the mechanisms of apoptosis and inflammatory factor production in F. necrophorum-induced neutrophils and macrophages (RAW246.7). After infection of macrophages with F. necrophorum, 5-ethynyl-2'-deoxyuridine labeling assays indicated that F. necrophorum inhibited macrophage proliferation in a time- and dose-dependent manner. Hoechst staining and DNA ladder assays showed significant condensation of the nucleus and fragmentation of genomic DNA in F. necrophorum-infected macrophages, Annexin V (FITC) and propidium iodide (PI) assay confirmed the emergence of apoptosis in the macrophages and sheep neutrophils with F. necrophorum compared with the control. The group with significant apoptosis was subjected to RNA sequencing (RNA-Seq), and the sequencing results revealed 2581 up- and 2907 downregulated genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis of the differentially expressed genes showed that F. necrophorum drove apoptosis and production of inflammatory factors by activating genes related to the Nuclear Factor-κB (NF-κB) and death receptor pathways. Meanwhile, quantitative reverse transcription PCR and Western blot validation results were consistent with the results of transcriptome sequencing analysis. In conclusion, F. necrophorum induced apoptosis and production of pro-inflammatory factors through the NF-κB and death receptor signaling pathway, providing a theoretical basis for further mechanistic studies on the prevention and control of F. necrophorum disease treatment.

An energy model for recognizing the prokaryotic promoters based on molecular structure.

Promoter is an important functional elements of DNA sequences, which is in charge of gene transcription initiation. Recognizing promoter have important help for understanding the relative life phenomena. Based on the concept that promoter is mainly determined by its sequence and structure, a novel statistical physics model for predicting promoter in Escherichia coli K-12 is proposed. The total energies of DNA local structure of sequence segments in the three benchmark promoter sequence datasets, the sole prediction parameter, are calculated by using principles from statistical physics and information theory. The better results are obtained. And a web-server PhysMPrePro for predicting promoter is established at http://202.207.14.87:8032/bioinformation/PhysMPrePro/index.asp, so that other scientists can easily get their desired results by our web-server.

Study on Inhibitory Effect of Volatile Oils in 16 Plants on Aspergillus flavus of Platycladi Semen / 中国实验方剂学杂志

Objective::To select volatile oils from 16 species of plants (Cymbopogon citratus, Pelargonium graveolens, Pinus tabulieformis, Litsea cubeba, Mentha haplocalyx, Zingiber officinale, Syzygium aromaticum, Curcuma longa, Zanthoxylum bungeanum, Cinnamomum cassia, Ocimum basilicum, Rosmarinus officinalis, Zanthoxylum schinifolium, Zanthoxylum armatum, Illicium verum, Myristica fragrans) that have good inhibitory effect on the growth of Aspergillus flavus. Method::Aspergillus flavus was isolated from the surface of Platycladi Semen medicinal materials by plate culture method. The volatile oils of 16 plants were extracted by steam distillation. The colony diameter of Aspergillus flavus was determined by fumigation of filter paper, and the effect of volatile oils on the growth of Aspergillus flavus was systematically studied. Result::Aspergillus flavus was successfully isolated from Platycladi Semen by means of morphological, microscopic and DNA barcoding identification methods, the bacteriostatic rates of the above 16 kinds of volatile oils against Aspergillus flavus were 2.93%, 0.05%, 0.37%, 76.07%, 0.34%, 0.15%, 50.05%, 8.51%, 1.43%, 58.20%, 0.07%, 2.60%, 8.73%, 100.00%, 52.62%, 0.07%, respectively. Conclusion::The volatile oils of 16 plants all have different degrees of antibacterial activities for Aspergillus flavus, and volatile oils of Zanthoxylum armatum, Litsea cubeba and Cinnamomum cassia have good inhibitory effect. This study can provide a theoretical basis for the prevention and control of Aspergillus flavus in the growth and storage of Platycladi Semen, and provide a basis for further research on plant volatile oil as bacteriostatic agents in the storage process of traditional Chinese medicine.

Study on the surface fungus diversity of commercially Platycladi semen based on high-throughput sequencing technology / 药学学报

The structural composition of the surface fungal community of commercially Platycladi semen was analyzed to reveal the surface fungal biodiversity and structural differences. Platycladi semen was collected from Henan, Shandong and Hong Kong, their DNA was extracted, ITS fragments in DNA were amplified by PCR. Miseq was sequenced on Illumina Hiseq 2500 platform after the PCR products were qualified for quality inspection. The sequence OTU cluster was obtained and bioinformatics analysis was carried out. Microbial communities were not observed in the eyes of the Platycladi semen in the three regions. Sequencing results showed that the surface microbial community had high biodiversity, but there were significant differences in species composition. Seven samples o Platycladi semen obtained 345 947 valid sequences, which were divided into 267 OTUs, 3 phylums. 18 classes, 40 orders, 82 families, 120 genus, 191 species fungi. At the genus level, Aspergillus is the dominant species, accounting for the highest proportion, reaching (93.36 ± 6.01)%. Seven samples were contaminated by Aspergillus flavus, and the pollution levels were 14.58%, 15.98%, 17.64%, 16.44%, 0.97%, 23.39% and 18.86%. Except sample No. 5, Aspergillus cibarius was the most abundant, the other six samples were Aspergillus niger, Aspergillus fumigatus and Aspergillus flavus as the core microflora. By analyzing the diversity of fungi distribution in different habitats, we can fully understand the fungi on the surface of Platycladi semen, lay a foundation for early risk warning of Aspergillus flavus contamination and its aflatoxin contamination, and provide a theoretical basis for the quality and safety of Platycladi semen.

Research Progress on Prevention and Control Measures of Aflatoxin in Chinese Medicinal Materials / 中国实验方剂学杂志

At present,traditional Chinese medicine(TCM) has attracted more and more attention from the international community.The demand for TCM is increasing in the world.The hidden dangers of potential quality and safety of TCM are also becoming increasingly prominent.Aflatoxin contamination has become one of the important factors affecting the safety of Chinese herbal medicines,and it will fundamentally affect human health and life safety.A variety of methods are used to reduce aflatoxins,however,there are few suitable methods that can be widely used in the cost-effective and large-scale promotion of Chinese herbal medicines.Therefore,it is of great significance to continue to study measures to solve the pollution problems of Aspergillus flavus and its toxins.This article summarizes the hazards and contamination status of aflatoxin,the prevention and control of the growth of A. flavus, and the measures for reducing aflatoxin,and looks ahead to the future prevention and control of A. flavus and its toxins,aiming at providing ideas for the pollution problem of A. flavus and its toxin,to ensure the quality of Chinese herbal medicines,so as to ensure clinical safety medication.

Effects of arbuscular mycorrhizal fungi on endogenous hormones in Salvia miltiorrhiza / 中国中药杂志

To investigate the dynamic changes of endogenous hormones contents in Salvia miltiorrhiza after the inoculation of Glomus versiforme(GV).The contents of endogenous hormones of ABA, ZR, GA, IAA and MeJA by ELISA were measured. Infection rata of GV reached plateau of 90% at the 90th d of inoculation; fresh weight of overground part and leaf number were significantly higher in GV group, with 2.7 and 1.96 fold than that of control; contents of all endogenous hormones apart from ABA in over- and under-ground part were markedly lower (P<0.05) in GV group at the 75th and 90th d, respectively, with 63% to 75% and 45% to 81% of that in control, and were significantly higher (P<0.05) in both over- and under-ground part in GV group at the 105th d, with 1.4 to 1.7 fold higher than that of control; content of ABA in underground part increased significantly at 60th, 75th and 105th d. Arbuscular mycorrhizal fungi could promote the growth of S. miltiorrhiza, and affect the dynamic changes of endogenous hormones contents in different infection periods.