Molecular Diversity and Evolutionary Relatedness of Paulownia Witches'-Broom Phytoplasma in Different Geographical Distributions in China.

To reveal the distribution and transmission pathway of Paulownia witches'-broom (PaWB) disease, which is caused by phytoplasmas related to genetic variation, and the adaptability to the hosts and environments of the pathogenic population in different geographical regions in China, in this study, we used ten housekeeping gene fragments, including rp, fusA, secY, tuf, secA, dnaK, rpoB, pyrG, gyrB, and ipt, for multilocus sequence typing (MLST). A total of 142 PaWB phytoplasma strains were collected from 18 provinces or municipalities. The results showed that the genetic diversity was comparatively higher among the PaWB phytoplasma strains, and substantially different from that of the other 16SrI subgroup strains. The number of gene variation sites for different housekeeping genes in the PaWB phytoplasma strains ranged from 1 to 14 SNPs. Among them, rpoB (1.47%) and dnaK (1.12%) had higher genetic variation, and rp (0.20%) had the least genetic variation. The tuf and rpoB genes showed the fixation of positively selected beneficial mutations in the PaWB phytoplasma populations, and all housekeeping genes except tuf followed the neutral evolutionary model. We found an absence of recombination among PaWB phytoplasma sequence types (STs) for each housekeeping gene except dnaK, and no evidence for such recombination events for concatenated sequences of PaWB phytoplasma strains. The 22 sequence types were identified among the concatenated sequences of seven housekeeping genes (rp, fusA, secY, secA, tuf, dnaK, and rpoB) from 105 representative strains. We analyzed all 22 STs by goeBURST algorithm, forming two clonal complexes (CCs) and three singletons. Among them, ST1, as the primary founder of CC1, had the widest geographical distribution, accounting for 72.38% of all strains, with a high frequency of shared sequence type. The results of phylogenetic analysis of the concatenated sequences further revealed that the 105 strains were clustered into two representative lineages of PaWB phytoplasma, with obvious geographical differentiation. The ST1 strains of highly homogeneous lineage-1 were a widespread and predominant population in diseased areas. Lineage-2 contained strains from Jiangxi, Fujian, and Shaanxi provinces, highlighting the close genetic relatedness of the strains in these regions, which was also consistent with the results of most single-gene phylogenetic analysis of each gene. We also found that the variability in the northwest China population was higher than in other geographical populations; the range of genetic differentiation between the south of the Yangtze River population and the Huang-huai-hai Plain (or southwest China) population was relatively large. The achieved diversity and evolution data, as well as the MLST technique, are helpful for epidemiological studies and guiding PaWB disease control decisions.

[Effects of IFN-γ on immunomodulation of mesenchymal stem cells isolated from fetal side of human placenta tissues].

AIM: To obtain fetal mesenchymal stem cells isolated from human placental tissue (hfPMSCs) and study the effects of IFN-γ on immunomodulatory property of hfPMSCs in vitro. METHODS: hfPMSCs were isolated from the fetal side of human placentas by enzyme digestion. Expressions of cell surface antigens CD73, CD90, CD105, CD14, CD34, CD45 and HLA-DR were tested by flow cytometry. The fetal origin of the placental cells was verified by DNA identity test using four known short tandem repeat (STR) polymorphic markers D2S1399, D10S2325, D18S535 and GATA198B05. After hfPMSCs were treated with 10 ng/mL IFN-γ, the expressions of IL-6, IL-8, IL-10 and HGF at both mRNA and protein levels were measured using quantitative real-time PCR (q-PCR) and ELISA. The expressions in controls without IFN-γ treatment were examined in the same way. RESULTS: The isolated cells expressed MSCs surface markers CD73, CD90 and CD105, but did not express CD14, CD34, CD45 and HLA-DR. For all the STR markers tested, the MSCs from the fetal side of the placenta carried the alleles of both maternal and paternal origin, indicative of the fetal genome. q-PCR indicated that the expression of IL6 mRNA in IFN-γ treated group was significantly higher than those in the control group (P<0.05), whereas the levels of IL-10 and HGF mRNA were down-regulated by IFN-γ treatment (P<0.05). ELISA revealed that IFN-γ treated group expressed strikingly the higher level of IL-6 protein compared with the control group (P<0.05), and the lower levels of IL-8, IL-10 and HGF (P<0.05). CONCLUSION: The method used in the study can obtain hfPMSCs from human placenta tissues, and IFN-γ has a negative effect on immune suppression function of the hfPMSCs.

Ameliorative and neuroprotective effect in MPTP model of Parkinson's disease by Zhen-Wu-Tang (ZWT), a traditional Chinese medicine.

AIM OF THE STUDY: Traditional Chinese medicine Zhen-Wu-Tang (ZWT) is a well-known PentaHerbs formula from "Treatise on Febrile Disease". This study is to elucidate its neuroprotective effect and mechanism of ameliorative effect of the syndrome of Parkinson's disease (PD). MATERIALS AND METHODS: The ameliorative effect of ZWT on symptom of PD through behavior tests including: swimming test, the tail suspension test and open-field test was investigated. The neuroprotective effect of dopaminergic neurons from the striatum and frontal cortex of brain was detected by high performance liquid chromatography with electrochemical detection (HPLC-ECD). RESULTS: This study proved that ZWT could ameliorate the typical symptom of PD and protect dopaminergic system. CONCLUSION: These results suggested that ZWT possessed protective and ameliorative properties of dopaminergic neurons.