Biology subjects

Tian, X.

Publications and source records attributed to Tian, X..

6 recordsLinked to original sources

bioRxiv2018

Risk Factors Associated with Dengue Virus Infection in Guangdong Province: a Community-based Case-control Study

BackgroundDengue fever is a mosquito-borne infectious disease, and it is now still epidemic in China, especially in Guangdong Province. Owing to the absence of dengue vaccination, effective preventive measure is critical for controlling of dengue fever. This study aimed to explore the individual risk factors of dengue virus infection in Guangdong Province, as well as to provide a scientific basis for prevention and supervision of dengue fever in future.\n\nMethodsA case-control study including 237 cases and 237 controls was performed. The data was collected from the epidemiological questionnaires. Univariate analysis was used for preliminary screening of 28 variables potentially related to dengue virus infection, and an unconditioned logistic regression analysis was used for multivariate analysis to analysis those statistically significant variables.\n\nResultsMultivariate analysis of the result showed three independent risk factors: activities in the park (odd ratio [OR]= 1.70, 95%CI 1.03 to 2.83), outdoor sports (OR= 1.67, 95%CI 1.07 to 2.62), and poor indoor daylight quality (OR= 2.27, 95%CI 1.00 to 5.15); and two protective factors: two persons per room (OR=0.43, 95%CI 0.28 to 0.67), three persons and above per room (OR=0.43, 95%CI 0.22 to 0.86), using air-condition (OR=0.43, 95%CI 0.20 to 0.93).\n\nConclusionThese results are conducive to learn the risk factors for dengue virus infection in Guangdong Province. It is crucial to provide effective and efficient strategy to improve environmental protection and anti-mosquito measures. In addition, more systematic studies are needed to explore the other potential risk factors for dengue fever infection.\n\nAuthor summaryDengue fever, one of the mosquito-borne infectious diseases, is mainly transmitted by Aedes aegypti in Asia and Southeast Asia countries. Since 1978, the incidence of dengue fever has markedly increased in China especially in Guangdong province. In order to formulate the effective prevention and control measures, we explored the risk factors of dengue virus infection in Guangdong Province by conducting a case-control study. In this study, 237 patients with dengue virus infection and 237 participants without dengue virus infection were included. Then through these questionnaires and data analysis, we found that activities in the park, outdoor sports, and poor indoor daylight quality significantly contributed to the residents risk of dengue virus infection. On the other hand, we observed that using air-condition and using anti-mosquito measures were effective personal prevention interventions.

scientific communication and education↗

bioRxiv2018

Vitamin A supplement after neonatal Streptococcus pneumoniae pneumonia alters CD4+T cell subset and inhibits allergic asthma in mice model

BackgroundPreviously, we showed that neonatal pneumonia caused by Streptococcus pneumoniae (S. pneumoniae) promoted adulthood ovalbumin (OVA) induced allergic asthma. Many studies have demonstrated that vitamin A deficiency induced the development of allergic asthma. Whether neonatal S. pneumoniae pneumonia promoted allergic asthma development was associated with vitamin A concentrations remains unclear.\n\nMethodsFemale BALB/c neonates were infected with S. pneumoniae strain D39 and subsequently treated with vitamin A. Vitamin A concentrations in lung, serum and liver were monitored on 2, 5, 7, 14, 21, 28 days post infection. Four weeks after infection, mice were sensitized and challenged with OVA to induce allergic airway disease (AAD) in early adulthood. Twenty-four hours after the final challenge, lung histo-pathology, cytokine concentrations in bronchoalveolar lavage fluid (BALF), airway hyperresponsiveness (AHR) and lung CD4+T cells were measured.\n\nResultsWe demonstrated that neonatal S. pneumoniae pneumonia induce lung vitamin A deficiency up to early adulthood. Moreover, neonatal S. pneumoniae pneumonia aggravated airway inflammatory cells accumulation and increased AHR during AAD, decreased Foxp3+Treg and Th1 productions remarkably, while Th2 cell expression was increased significantly. Further study indicated that vitamin A supplement after neonatal S. pneumoniae pneumonia can promote Foxp3+Treg and Th1 productions, decrease Th2 cell expressions, alleviate AHR and inflammatory cells infiltration during AAD.\n\nConclusionsUsing a mouse model, we demonstrate that Vitamin A supplement after neonatal Streptococcus pneumoniae pneumonia alters the CD4+T cell subset and inhibits the development of early adulthood allergic asthma.

immunology↗

bioRxiv2018

FRMPD2: a novel GluN2A-interacting scaffold protein in synaptic excitatory transmission

The scaffold proteins FRMPD2 is localized at the basolateral membranes of polarized epithelial cells and associated with tight junction formation. But the expression and function of FRMPD2 in vivo remain unknown. Here, we found that postsynaptic FRMPD2 effectively alters the neuronal excitability by regulating NMDARs-component excitatory synaptic transmission in adult hippocampus. FRMPD2 anchors the NMDAR subunit GluN2A at the synapses without changing the total NMDAR expression. By using of Co-IP, Pull Down and SPR, the second PDZ (PDZ2) domain of FRMPD2 direct and binds to the C-terminus of GluN2A. Our study discover that a novel scaffold protein FRMPD2 regulates synaptic excitatory in a PDZ2 domain-dependent manner in adult hippocampus.

neuroscience↗

bioRxiv2018

Root Colonization and Growth Promotion of Soybean, Wheat and Chinese Cabbage by Bacillus cereus YL6

Phosphate-solubilizing bacteria (PSB) have been isolated and used in agricultural production. However, comprehensive research on PSB colonizing the rhizosphere of different plants and promoting plant growth is lacking. This study was conducted to study the growth-promoting effects and colonizing capacity of the PSB strain YL6. The YL6 strain not only increased the biomass of pot-planted soybean and wheat but also increased the yield and growth of Chinese cabbage under field conditions. The promotion of growth in these crops by strain YL6 was related to its capacities to dissolve inorganic and organic phosphorus and to produce a certain amount of indole-3-acetic (IAA) and gibberellin (GA). After YL6 was applied to soybean, wheat and Chinese cabbage, the rhizosphere soil available phosphorus (available P) content increased by 120.16%, 62.47% and 7.21%, respectively, and the plant total phosphorus increased by 198.60%, 6.20% and 78.89%, respectively, compared with those of plants without the addition of YL6. To determine whether the phosphate solubilizing bacteria colonized these plants, YL6 labeled with green fluorescent protein (YL6-GFP) was inoculated into plant rhizospheres. YL6-GFP first colonized the root surface and hairs and then penetrated into intercellular spaces and vessels. Collectively, these results demonstrate that YL6 promoted the growth of three different crops and colonized them in a similar way and therefore provide a solid foundation for probing into mechanisms by which phosphate-solubilizing bacteria affect plant growth.

microbiology↗

bioRxiv2017

CRISPR-Cas12a target binding unleashes single-stranded DNase activity

CRISPR-Cas12a (Cpf1) proteins are RNA-guided DNA targeting enzymes that bind and cut DNA as components of bacterial adaptive immune systems. Like CRISPR-Cas9, Cas12a can be used as a powerful genome editing tool based on its ability to induce genetic changes in cells at sites of double-stranded DNA (dsDNA) cuts. Here we show that RNA-guided DNA binding unleashes robust, non-specific single-stranded DNA (ssDNA) cleavage activity in Cas12a sufficient to completely degrade both linear and circular ssDNA molecules within minutes. This activity, catalyzed by the same active site responsible for site-specific dsDNA cutting, indiscriminately shreds ssDNA with rapid multiple-turnover cleavage kinetics. Activation of ssDNA cutting requires faithful recognition of a DNA target sequence matching the 20-nucleotide guide RNA sequence with specificity sufficient to distinguish between closely related viral serotypes. We find that target-dependent ssDNA degradation, not observed for CRISPR-Cas9 enzymes, is a fundamental property of type V CRISPR-Cas12 proteins, revealing a fascinating parallel with the RNA-triggered general RNase activity of the type VI CRISPR-Cas13 enzymes.\n\nOne Sentence SummaryCas12a (Cpf1) and related type V CRISPR interference proteins possess non-specific, single-stranded DNase activity upon activation by guide RNA-dependent DNA binding.

biochemistry↗

bioRxiv2017

Cellular Interplay and Cytokine Hierarchy Cause Pathological Cardiac Hypertrophy in RAF1-Mutant Noonan Syndrome

Noonan syndrome (NS) is caused by mutations in RAS/ERK pathway genes, and is characterized by craniofacial, growth, cognitive and cardiac defects. NS patients with kinase-activating RAF1 alleles typically develop pathological left ventricular hypertrophy (LVH), which is reproduced in Raf1L613V/+ knock-in mice. Here, using inducible Raf1L613V expression, we show that LVH results from the interplay of cardiac cell types. Cardiomyocyte Raf1L613V enhances Ca2+ sensitivity and cardiac contractility without causing hypertrophy. Raf1L613V expression in cardiomyocytes or activated fibroblasts exacerbates pressure overload-evoked fibrosis. Endothelial/endocardial (EC) Raf1L613V causes cardiac hypertrophy without affecting contractility. Co-culture and neutralizing antibody experiments reveal a cytokine (TNF/IL6) hierarchy in Raf1L613V-expressing ECs that drives cardiomyocyte hypertrophy in vitro. Furthermore, post-natal TNF inhibition normalizes the increased wall thickness and cardiomyocyte hypertrophy in vivo. We conclude that NS cardiomyopathy involves cardiomyocytes, ECs, and fibroblasts, TNF/IL6 signaling components represent potential therapeutic targets, and abnormal EC signaling might contribute to other forms of LVH.

cell biology↗