Research on Electric Field-Induced Catalysis Using Single-Molecule Electrical Measurement.

The role of catalysis in controlling chemical reactions is crucial. As an important external stimulus regulatory tool, electric field (EF) catalysis enables further possibilities for chemical reaction regulation. To date, the regulation mechanism of electric fields and electrons on chemical reactions has been modeled. The electric field at the single-molecule electronic scale provides a powerful theoretical weapon to explore the dynamics of individual chemical reactions. The combination of electric fields and single-molecule electronic techniques not only uncovers new principles but also results in the regulation of chemical reactions at the single-molecule scale. This perspective focuses on the recent electric field-catalyzed, single-molecule chemical reactions and assembly, and highlights promising outlooks for future work in single-molecule catalysis.

Clostridium butyricum improves cognitive dysfunction in ICV-STZ-induced Alzheimer's disease mice via suppressing TLR4 signaling pathway through the gut-brain axis.

In recent years, the relationship between gut-brain axis and Alzheimer's disease (AD) attracted increasing attention. The aim of this study is to investigate the therapeutic effect of Clostridium butyricum (CB) on intraventricular injection of streptozotocin (ICV-STZ)-induced mice and the potential mechanisms. ICV-STZ mice were treated with CB by gavage for 21 consecutive days. The pharmacological effect of CB was assessed by behavior test, brain tissue H&E staining and tau protein phosphorylation levels of hippocampus tissues. The expression levels of TLR4, MYD88, NF-κB p65, TNF-α, iNOS, Occludin and ZO-1 in hippocampal and colonic tissues were detected by Western-blot method. 16S rRNA gene sequencing analysis was used to analyze the intestinal microbiota of mice. The results showed that CB improved the cognitive dysfunction of ICV-STZ mice, restored the structure and cell number of hippocampal and cortical neurons, decreased the protein levels of pSer404-tau protein in hippocampal tissues and TLR4, MYD88, NF-κB p65 and iNOS in hippocampal and colonic tissues, and increased the protein levels of Occludin and ZO-1 in colonic tissues. Meanwhile, CB reversed the changes of intestinal microbiota in AD mice. Therefore, the mechanisms of cognitive function and brain pathological changes in AD mice improved by CB may be related to the regulation of TLR4 signaling pathway and intestinal microbiota. This study supports the potential anti-AD effect of CB and initially revealed its pharmacological mechanism of CB, providing a theoretical basis for further clinical application of CB.

Chemical Sensors using Single-Molecule Electrical Measurements.

Driven by the digitization and informatization of contemporary society, electrical sensors are developing toward minimal structure, intelligent function, and high detection resolution. Single-molecule electrical measurement techniques have been proven to be capable of label-free molecular recognition and detection, which opens a new strategy for the design of efficient single-molecule detection sensors. In this review, we outline the main advances and potentials of single-molecule electronics for qualitative identification and recognition assays at the single-molecule level. Strategies for single-molecule electro-sensing and its main applications are reviewed, mainly in the detection of ions, small molecules, oligomers, genetic materials, and proteins. This review summarizes the remaining challenges in the current development of single-molecule electrical sensing and presents some potential perspectives for this field.

Radix Rehmanniae Praeparata (Shu Dihuang) exerts neuroprotective effects on ICV-STZ-induced Alzheimer's disease mice through modulation of INSR/IRS-1/AKT/GSK-3ß signaling pathway and intestinal microbiota.

Radix Rehmanniae Praeparata (RRP, Shu Dihuang in Cinese) is widely used as primal medicine in Chinese herbal formula for the treatment of Alzheimer's disease (AD). However, the underlying mechanism of RRP for AD remains unclear. The aim of this study was to investigate the therapeutic effect of RRP on intracerebroventricular injection of streptozotocin (ICV-STZ)-induced AD model mice and its potential mechanism. ICV-STZ mice were continuously gavaged with RRP for 21 days. The pharmacological effects of RRP were evaluated by behavioral tests, brain tissue H&E staining and hippocampal tau protein phosphorylation levels. The expression levels of insulin receptor (INSR), IRS-1, pSer473-AKT/AKT and pSer9-GSK-3ß/GSK-3ß proteins in hippocampal and cortical tissues were detected by Western-blot method. The 16S rRNA gene sequencing was used to analyze the changes of intestinal microbiota in mice. The compounds in RRP were analyzed by mass spectrometry and their binding ability to INSR proteins was detected by molecular docking. The results showed that RRP ameliorated cognitive dysfunction and neuronal pathological changes of brain tissue in ICV-STZ mice, reduced tau protein hyperphosphorylation, INSR, IRS-1, pSer473-AKT/AKT, and pSer9-GSK-3ß/GSK-3ß levels in hippocampal and cortical tissues. Meanwhile, RRP reversed ICV-STZ-induced dysregulation of intestinal microbiota in AD mice. Mass spectrometry analysis showed that the RRP consisted mainly of seven compounds, namely Acteoside (Verbascoside), 5-Hydroxymethyl-2-furaldehyde (5-HMF), Apigenin7-O-glucuronide, Icariin, Gallic acid, Quercetin-3ß-D-glucoside, and Geniposide. Molecular docking results further indicated that the compounds in RRP have binding ability to INSR protein and potential multiple synergistic effects. RRP ameliorates cognitive dysfunction and brain histopathological changes in AD mice. The mechanism of RRP ameliorating AD may be related to the regulation of INSR/IRS-1/AKT/GSK-3ß signaling pathway and intestinal microbiota. This study supports the potential anti-AD efficacy of RRP and initially reveals the pharmacological mechanism of RRP, providing a theoretical basis for further clinical application of RRP.

Molecular identification and subtyping of Blastocystis sp. in laboratory rats in China.

Blastocystis sp. is a ubiquitous protist that has been frequently reported in humans and animals worldwide. A total of 355 fecal samples of experimental rats were collected from four laboratory rearing facilities in China, and Blastocystis sp. was detected by PCR amplification of the partial small subunit ribosomal (SSU) rRNA gene. Twenty-nine (8.2%, 29/355) samples were positive for Blastocystis sp., with the highest infection rate (20.7%, 24/116) in rats of the Zhengzhou1, followed by that in the Zhengzhou2 (5.0%, 2/40), Shenyang (3.0%, 3/100) and Wuhan (0) rearing facilities. Among the three rat strains, Sprague-Dawley (SD) rats had higher infection rates (11.3%, 17/151) compared to Wistar rats (8.7%, 9/104) and spontaneously hypertensive (SH) rats (3.0%, 3/100). Two Blastocystis sp. subtypes (ST4 and ST7) were identified. ST4 was the predominant subtype detected in 26 samples (89.7%). A phylogenetic analysis demonstrated that the sequences of ST4 and ST7 obtained in this study were clustered with their reference subtypes. To our knowledge, this is the first report of Blastocystis sp. in experimental rats in China. Pathogen infections in laboratory animals need to be monitored due to fecal-oral transmission.

TITLE: Identification moléculaire et sous-typage de Blastocystis sp. chez des rats de laboratoire en Chine. ABSTRACT: Blastocystis sp. est un protiste omniprésent qui a été fréquemment signalé chez l'homme et les animaux du monde entier. Un total de 355 échantillons fécaux de rats de laboratoire ont été prélevés dans quatre installations d'élevage en laboratoire en Chine et Blastocystis sp. a été détectée par amplification par PCR du gène partiel de la petite sous-unité de l'ARNr ribosomique (SSU). Vingt-neuf échantillons (8,2 %, 29/355) étaient positifs pour Blastocystis sp., avec le taux d'infection le plus élevé (20,7 %, 24/116) chez les rats des élevages de Zhengzhou1, suivi de ceux de Zhengzhou2 (5,0 %, 2/40), Shenyang (3,0 %, 3/100) et Wuhan (0). Parmi les trois souches de rats, les rats Sprague-Dawley (SD) avaient un taux d'infection plus élevé (11,3 %, 17/151) que les rats Wistar (8,7 %, 9/104) et les rats spontanément hypertendus (SH) (3,0 %, 3/100). Deux sous-types de Blastocystis sp. ont été identifiés, ST4 et ST7. ST4 était le sous-type prédominant, détecté dans 26 échantillons (89,7 %). Une analyse phylogénétique a démontré que les séquences de ST4 et ST7 obtenues dans cette étude étaient groupées avec leurs sous-types de référence. À notre connaissance, il s'agit du premier signalement de Blastocystis sp. chez des rats de laboratoire en Chine. Les infections pathogènes chez les animaux de laboratoire doivent être surveillées en raison de la transmission fécale-orale.

Molecular characterization of Blastocystis sp. in captive wildlife in Bangladesh National Zoo: Non-human primates with high prevalence and zoonotic significance.

Blastocystis sp. is a protozoan parasite, commonly found in the gastrointestinal tracts of animals and humans globally. The parasitic species has wide genetic diversity. Currently the mammalian and avian isolates of the parasite are grouped into 17 well known subtypes (STs), of which ten (ST1-ST9, ST12) are reported in humans. To assess the genetic diversity of Blastocystis sp. in wildlife, a total of 200 fresh fecal samples were collected from 32 mammalian wildlife species in Bangladesh National Zoo. Blastocystis sp. was screened and subtyped by PCR amplification and sequencing of the small subunit ribosomal RNA (SSU rRNA) gene. The minimum prevalence of Blastocystis sp. infection was 15.5% (31/200) in zoo animals. Eight out of 32 wildlife animal species (25.0%) were infected with Blastocystis sp. Among them, the occurrence of Blastocystis sp. was higher in non-human primates (NHPs) (31.8%) than that in herbivores (4.9%) and carnivores (0). Nucleotide sequence analysis of the SSU rRNA gene revealed seven different Blastocystis sp. subtypes, such as ST1, ST2, ST3, ST10, ST11, ST13 and ST14 in the wild animals. ST3 was the dominant subtype (41.9%, 13/31) being detected in NHPs. Of the 31 Blastocystis sp. isolates from the wild animals, 24 (77.4%) isolates belonged to the most common subtypes (ST1 to ST3) found in humans. This is the first molecular study of Blastocystis sp. in wild animals in Bangladesh. This study highlights the remarkable genetic diversity in Blastocystis sp. isolates from zoo animals and provides the first molecular evidence from spotted deer, gayal and grey langur. Due to circulation of large percentage of potentially zoonotic subtypes in the wild animals, there is a higher risk of zoonotic transmission of Blastocystis sp. in the zoo keepers and visitors.

Genetic variability and phylogeny of current Chinese porcine epidemic diarrhea virus strains based on spike, ORF3, and membrane genes.

Since late 2010, the outbreak of porcine epidemic diarrhea (PED) in China has resulted in the deaths of millions of suckling piglets. The main cause of the disease outbreak was unknown. In this study, partial spike (S), ORF3, and membrane (M) genes amplified from these variants were sequenced and analyzed. The results showed that the variants could be clustered into one to three subgroups and suggested that S genes were variable, while M genes were relatively conserved. Moreover, in comparison with the vaccine strain CV777, sequence alignment analyses revealed that the S genes of the newly isolated strains contained several mutations at the aa level. It is possible that these mutations have changed the hydrophobicity of the S protein and influenced the viral antigenicity and virulence. Interestingly, homology analyses based on ORF3 demonstrated that the isolates had an intact opening reading frame (ORF), which were different from the attenuated DR13 strain. In conclusion, the widespread PED virus (PEDV) isolates had virulent characteristics. Additionally, the high degree of variation in the genes, particularly S genes, might provide an explanation for the poor immunity and rapid spread of the disease.

Different infection routes of avian influenza A (H5N1) virus in mice.

The continuing outbreaks of avian influenza A H5N1 virus infection in Asia and Africa have caused worldwide concern because of the high mortality rates in poultry, suggesting its potential to become a pandemic influenza virus in humans. The transmission route of the virus among either the same species or different species is not yet clear. Broilers and BABL/c mice were inoculated with the H5N1 strain of influenza A virus isolated from birds. The animals were inoculated with 0.1 mL 10(6.83) TCID(50) of H5N1 virus oronasally, intraperitoneally and using eye drops. The viruses were examined by virological and pathological assays. In addition, to detect horizontal transmission, in each group, healthy chicks and mice were mixed with those infected. Viruses were detected in homogenates of the heart, liver, spleen, kidney and blood of the infected mice and chickens. Virus antigen was not detected in the spleen, kidney or gastrointestinal tract, but detected by Plaque Forming Unit (PFU) assay in the brain, liver and lung without degenerative change in these organs (in the group inoculated using eye drops. The detection results for mice inoculated using eye drops suggest that this virus might have a different tissue tropism from other influenza viruses mainly restricted to the respiratory tract in mice. All chicken samples tested positive for the virus, regardless of the method of inoculation. Avian influenza A H5N1 viruses are highly pathogenic to chickens, but its virulence in other animals is not yet known. To sum up, the results suggest that the virus replicates not only in different animal species but also through different routes of infection. In addition, the virus was detection not only in the respiratory tract but also in multiple extra-respiratory tissues. This study demonstrates that H5N1 virus infection in mice can cause systemic disease and spread through potentially novel routes within and between mammalian hosts.