A Core Genome Multilocus Sequence Typing Scheme for Proteus mirabilis.

Objective: A core genome multilocus sequence typing (cgMLST) scheme to genotype and identify potential risk clonal groups (CGs) in Proteus mirabilis. Methods: In this work, we propose a publicly available cgMLST scheme for P. mirabilis using chewBBACA. In total 72 complete P. mirabilis genomes, representing the diversity of this species, were used to set up a cgMLST scheme targeting 1,842 genes, 635 unfinished (contig, chromosome, and scaffold) genomes were used for its validation. Results: We identified a total of 205 CGs from 695 P. mirabilis strains with regional distribution characteristics. Of these, 159 unique CGs were distributed in 16 countries. CG20 and CG3 carried large numbers of shared and unique antibiotic resistance genes. Nine virulence genes ( papC, papD, papE, papF, papG, papH, papI, papJ, and papK) related to the P fimbrial operon that cause severe urinary tract infections were only found in CG20. These CGs require attention due to potential risks. Conclusion: This research innovatively performs high-resolution molecular typing of P. mirabilis using whole-genome sequencing technology combined with a bioinformatics pipeline (chewBBACA). We found that the CGs of P. mirabilis showed regional distribution differences. We expect that our research will contribute to the establishment of cgMLST for P. mirabilis.

Mechanism of Genetic Robustness / 中国生物化学与分子生物学报

Genetic robustness refers to the fact that an organism has a buffer system that can maintain normal development, even if the existence of genetic mutations during biological development. Previous research on the underlying mechanism of genetic robustness mainly involves in genetic redundancy and distributed robustness, both of which are triggered at the protein level. Recently, a new genetic compensation response (GCR) mechanism has been discovered in zebrafish, which occurs in knockout rather than knockdown individuals and is triggered upstream of protein feedback regulation. Since there are many concepts related to genetic robustness, this review attempts to clarify these concepts from the types of compensation genes and triggering modes. Additionally, we aim to understand the latest discovered GCR mechanism and look forward to studying the function of specific genes based on functional compensation mechanisms.

Effective Antiviral Activity of the Tyrosine Kinase Inhibitor Sunitinib Malate against Zika Virus / 감염과화학요법

Background@#(Introduction): Zika virus (ZIKV), a mosquito-borne flavivirus, causes the outbreaks of Latin America in 2015 - 2016, with the incidence of neurological complications. Sunitinib malate, an orally bioavailable malate salt of the tyrosine kinase inhibitor, is suggested as a broadspectrum antiviral agent against emerging viruses like severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2. @*Materials and Methods@#This study investigated the antiviral efficacy and antiviral mechanisms of sunitinib malate against ZIKV infection using cytopathic effect reduction, virus yield, and time-of-addition assays. @*Results@#Sunitinib malate concentration-dependently reduced ZIKV-induced cytopathic effect, the expression of viral proteins, and ZIKV yield in supernatant with 50% inhibitory concentration (IC 50 ) value of 0.015 μM, and the selectivity index of greater than 100 against ZIKV infection, respectively. Sunitinib malate had multiple antiviral actions during entry and post-entry stages of ZIKV replication. Sunitinib malate treatment at entry stage significantly reduced the levels of ZIKV RNA replication with the reduction of (+) RNA to (-) RNA ratio and the production of new intracellular infectious particles in infected cells. The treatment at post-entry stage caused a concentration-dependent increase in the levels of ZIKV (+) RNA and (-) RNA in infected cells, along with enlarging the ratio of (+) RNA to (-) RNA, but caused a pointed increase in the titer of intracellular infectious particles by 0.01 and 0.1 μM, and a substantial decrease in the titer of intracellular infectious particles by 1 μM. @*Conclusion@#The study discovered the antiviral actions of sunitinib malate against ZIKV infection, demonstrating a repurposed, host-targeted approach to identify potential antiviral drugs for treating emerging and global viral diseases.

Endophilin-A2-mediated endocytic pathway is critical for enterovirus 71 entry into caco-2 cells.

Enterovirus 71 (EV71) is typically transmitted by the oral-faecal route and initiates infection upon crossing the intestinal mucosa. Our limited understanding of the mechanisms by which it crosses the intestinal mucosa has hampered the development of effective therapeutic options. Here, using an RNA interference screen combined with chemical inhibitors or the overexpression of dominant negative proteins, we found that EV71 entry into Caco-2 cells, a polarized human intestinal epithelial cell line, does not involve clathrin- and caveolae-dependent endocytic pathways or macropinocytosis but requires GTP-binding protein dynamin 2 and cytoskeleton remodelling. The use of siRNAs targeting endophilin family members revealed that endophlin-A2 is essential for the uptake of EV71 particles by Caco-2 cells. Subcellular analysis revealed that internalized EV71 virions largely colocalized with endophilin-A2 at cytomembrane ruffles and in the perinuclear area. Combined with viral entry kinetics, these data suggest that EV71 enters Caco-2 cells mainly via an endophilin-A2-mediated endocytic (EME) pathway. Finally, we showed that internalized EV71 virions were transported to endosomal sorting complex required for transport (ESCRT)-related multivesicular bodies (MVBs). These data provide attractive therapeutic targets to block EV71 infection.

Cis-3-O-p-hydroxycinnamoyl Ursolic Acid Induced ROS-Dependent p53-Mediated Mitochondrial Apoptosis in Oral Cancer Cells

Cis-3-O-p-hydroxycinnamoyl ursolic acid (HCUA), a triterpenoid compound, was purified from Elaeagnus oldhamii Maxim. This traditional medicinal plant has been used for treating rheumatoid arthritis and lung disorders as well as for its anti-inflammation and anticancer activities. This study aimed to investigate the anti-proliferative and apoptotic-inducing activities of HCUA in oral cancer cells. HCUA exhibited anti-proliferative activity in oral cancer cell lines (Ca9-22 and SAS cells), but not in normal oral fibroblasts. The inhibitory concentration of HCUA that resulted in 50% viability was 24.0 µM and 17.8 µM for Ca9-22 and SAS cells, respectively. Moreover, HCUA increased the number of cells in the sub-G1 arrest phase and apoptosis in a concentration-dependent manner in both oral cancer cell lines, but not in normal oral fibroblasts. Importantly, HCUA induced p53-mediated transcriptional regulation of pro-apoptotic proteins (Bax, Bak, Bim, Noxa, and PUMA), which are associated with mitochondrial apoptosis in oral cancer cells via the loss of mitochondrial membrane potential. HCUA triggered the production of intracellular reactive oxygen species (ROS) that was ascertained to be involved in HCUA-induced apoptosis by the ROS inhibitors YCG063 and N-acetyl-L-cysteine. As a result, HCUA had potential antitumor activity to oral cancer cells through eliciting ROS-dependent and p53-mediated mitochondrial apoptosis. Overall, HCUA could be applicable for the development of anticancer agents against human oral cancer.

[Dynamic change of four triterpenic acids contents in different organs of loquat (Eriobotrya japonica) and phenology].

The loquat is widely cultivated in China, its succulent fruits, leaves and flower are used as a traditional medicine for the treatment of many diseases. The study is aimed to analyse the content of the four triterpene compounds ( ursolic acid, corosolic acid, maslinic acid, oleanolic acid) in different organs, and investigate the dynamic changes in different phenological period. The triterpenic acids content in the samples was measured by HPLC based on the plant phenological observations. The results showed that order of four triterpenic acids content in different organs from high to low was defoliation (23.2 mg x g(-1)) > mature leaves (21.7 mg x g(-1)) > young leaves (17.5 mg x g(-1)) > fruits (7.36 mg x g(-1)) > flowers (6.40 mg x g(-1)). The triterpenic acids were not detected in the seeds. The total amount of the four triterpenic acids in the loquat leaves collected in the different phenological stages of sprout, flower bud, blossom and fruit varied between 17.8 and 26.2 mg x g(-1) (defoliation), 16.5 and 23.5 mg x g(-1) (mature leaves), 14.7 and 21.5 mg x g(-1) (young leaves), respectively. The content increased progressively with the leaf development, maturation and aging. There was a higher level of the dry material and triterpenic acids accumulation in the mature leaves during fruit enlargement. This paper attempts to present the case for medicinal plants of a broad geographical distribution to study on the secondary metabolites and harvesting time.

The role of lipid rafts in the early stage of Enterovirus 71 infection.

BACKGROUND/AIMS: Although it has been widely accepted that Enterovirus 71 (EV71) enters permissive cells via receptor-mediated endocytosis, the details of entry mechanism for EV71 still need more exploration. This study aimed to investigate the role of lipid rafts in the early stage of EV71 Infection. METHODS: The effect of cholesterol depletion or addition of exogenous cholesterol was detected by immunofluorescence assays and quantitative real-time PCR. Effects of cholesterol depletion on the association of EV71 with lipid rafts were determined by flow cytometry and co-immunoprecipitation assays. Localization and internalization of EV71 and its receptor were assayed by confocal microscpoy and sucrose gradient analysis. The impact of cholesterol on the activation of phosphoinositide 3'-kinase/Akt signaling pathway during initial virus infection was analyzed by Western-blotting. RESULTS: Disruption of membrane cholesterol by a pharmacological agent resulted in a significant reduction in the infectivity of EV71. The inhibitory effect could be reversed by the addition of exogenous cholesterol. Cholesterol depletion post-infection did not affect EV71 infection. While virus bound equally to cholesterol-depleted cells, EV71 particles failed to be internalized by cholesterol-depleted cells. EV71 capsid protein co-localized with cholera toxin B, a lipid-raft-dependent internalization marker. CONCLUSION: Lipid rafts play a critical role in virus endocytosis and in the activation of PI3K/Akt signaling pathway in the early stage of EV71 infection.

Transplantation of bone marrow-derived mesenchymal stem cells after regional hepatic irradiation ameliorates thioacetamide-induced liver fibrosis in rats.

BACKGROUND: Recent studies have demonstrated that bone marrow-derived mesenchymal stem cells (BM-MSCs) can potentially revert liver fibrosis, but it is not known if preparative hepatic irradiation (HIR) contributes to the therapeutic effect of transplanted BM-MSCs. In this study, we investigate the effects of HIR on transplanted BM-MSCs in cirrhotic rats and the underlying mechanism by which mesenchymal stem cells (MSCs) relieve liver fibrosis. MATERIALS AND METHODS: The BM-MSCs from male rats were labeled with CM-Dil and injected via portal vein into two groups of thioacetamide-induced cirrhotic rats, and the controls were injected with the same volume of saline. The right hemiliver of one cirrhotic rat group was irradiated (15 Gy) 4 d before transplantation. Liver function tests and histologic experiments were performed, and the liver population of BM-MSCs was estimated. RESULTS: The transplantation of MSCs alleviated liver fibrosis and reduced expression of transforming growth factor-ß1, Smad2, collagen type I, and α-SMA. HIR preconditioning promoted homing and repopulation of MSCs and resulted in better treatment outcomes. CONCLUSIONS: HIR preconditioning enhances the effect of BM-MSCs in improving thioacetamide-induced liver fibrosis in rats by promoting their homing and repopulation. BM-MSCs may function by inhibiting transforming growth factor-ß1-Smad signaling pathway in the liver.

[Microscopic autofluorescence study of cardiac cancer and normal gastric tissues].

OBJECTIVE: To investigate the microscopic autofluorescent characteristics of cardiac cancer and autofluorescence distribution in different layers of gastric tissues. METHODS: A double-channel laser scanning confocal microscopy with Argon ion laser (excitation wavelength 488 nm) and Helium-Neon laser (excitation wavelength 543 nm) were used to detect the autofluorescence emitted from 16 surgical specimens of cardiac cancer and corresponding normal gastric tissue. The autofluorescence image was analyzed between the cardiac cancer tissue and normal gastric tissue. RESULTS: Autofluorescence was detected successfully in cardiac carcinoma and corresponding normal gastric corpus tissues of all 16 cases. In different layers of gastric tissue, fluorescence presented the strongest signal in submucosa,the second strong in luminal propria with fluorescence mostly distributed in the glands, fluorescence signal from gastric cancer was significantly decreased compared with those in the different layers of normal tissues (P< 0.01). CONCLUSION: There are significant differences in the shape, color, distribution and fluorescence intensity of microscopic autofluorescence between cardiac cancer tissues and normal gastric corpus tissues.