分类: 医学、药学 >> 临床医学 提交时间: 2020-02-28
摘要: Here we reported a case of asymptomatic carrier of SARS-CoV-2 infection. A 50-year old woman, lived with her husband in Anqing(Anhui, China) with no significant past medical history, travel history to Wuhan or adjacent area, or exposure to wild animals. She took throat swab test for SARS-CoV-2 nucleic acid due to her husband’s close contact with patients who had SARS-CoV-2 infection. Her results were confirmed positive on February 6, 2020. But she did not report elevation of temperature measurement, nor respiratory or gastrointestinal symptoms and her chest CT scan showed no significant abnormalities. She was hospitalized on February 6 and treated with antiviral agents. During her hospitalization, apart from a mild elevation of liver enzymes after 10-day treatment of lopinavir/ritonavir, she was asymptomatic, with her blood cell count, live and renal function largely normal. Her subcutaneous oxygen saturation stayed above 97%. Chest CT scan was repeated on February 11 and 20, and both were negative for signs of viral pneumonia. Notably, a second set of throat swabs and anal swabs were sent to test for SARS-CoV-2 on February 19, and the results were still confirmed positive. This is a confirmed case of asymptomatic carrier of SARS-CoV-2 infection. Her persistent positive findings in both throat and anal swabs suggested the possibility of healthy carrier of the virus, which adds to the difficulty in preventing transmission of the disease.
分类: 生物学 >> 生物物理学 提交时间: 2016-05-12
摘要: Ubiquitination is a post-translational modification that is involved in myriad cellar regulation and disease pathways. The ubiquitin-conjugating enzyme (E2) is an important player in the ubiquitin transfer pathway. Although many E2 structures are available, not all E2 families have known structures, and three-dimensional structures from fungal organisms other than yeast are lacking. We report here the crystal structure of UbcA1, which is a novel ubiquitin-conjugating enzyme identified from the edible and medicinal mushroom Agrocybe aegerita and displays potential antitumor properties. The protein belongs to the Ube2w family and shows similar biochemical characteristics to human Ube2w, including monomer-dimer equilibrium in solution, alpha-NH2 ubiquitin-transfer activity and a mechanism to recognize backbone atoms of intrinsically disordered N-termini in substrates. Its structure displays a unique C-terminal conformation with an orientation of helix alpha 3 that is completely different from the reported E2 structures but similar to a recently reported NMR ensemble of Ube2w. A mutagenesis study on this novel enzyme revealed that an intact C-terminus is significant for protein dimerization and enzymatic activity. As the first crystallized full-length protein of this family, UbcA1 may supersede the truncated X-ray structure of Ube2w (PDB entry 2A7L) as the representative structure of the Ube2w family.
分类: 生物学 >> 生物物理学 提交时间: 2016-05-12
摘要: Protein-protein interaction (PPI) networks serve as a powerful tool for unraveling protein functions, disease-gene and disease-disease associations. However, a direct strategy for integrating protein interaction, protein function and diseases is still absent. Moreover, the interrelated relationships among these three levels are poorly understood. Here we present a novel systematic method to integrate protein interaction, function, and disease networks. We first identified topological modules in human protein interaction data using the network topological algorithm (NeTA) we previously developed. The resulting modules were then associated with functional terms using Gene Ontology to obtain functional modules. Finally, disease modules were constructed by associating the modules with OMIM and GWAS. We found that most topological modules have cohesive structure, significant pathway annotations and good modularity. Most functional modules (70.6%) fully cover corresponding topological modules, and most disease modules (88.5%) are fully covered by the corresponding functional modules. Furthermore, we identified several protein modules of interest that we describe in detail, which demonstrate the power of our integrative approach. This approach allows us to link genes, and pathways with their corresponding disorders, which may ultimately help us to improve the prevention, diagnosis and treatment of disease.
分类: 生物学 >> 生物物理学 >> 生物物理、生物化学与分子生物学 提交时间: 2016-05-11
摘要: Long noncoding RNAs (lncRNAs) are pervasively transcribed in the human genome. Recent studies suggest that the involvement of IncRNAs in human diseases could be far more prevalent than previously appreciated. Here we have identified a lncRNA termed Lnc_bc060912 whose expression is increased in human lung and other tumors. Lnc_bc060912 is 1.2 kb in length and is composed of two exons. The expression of Lncbc060912, was repressed by p53. Lnc_bc060912 suppressed cell apoptosis. Using a recently developed method for RNA-pulldown with formaldehyde cross-linking, we found that Lnc_bc060912 interacted With the two DNA damage repair proteins PARP1 and NPM1. Together, these results suggest that Lnc_bc060912, via PARP1 and NPM1, affects cell apoptosis and may play important roles in tumorigenesis and cancer progression.
分类: 生物学 >> 生物物理学 >> 肿瘤学 提交时间: 2016-05-11
摘要: Esophageal Squamous Cell Carcinoma (ESCC) is among the most common malignant cancers worldwide. In the past, extensive efforts have been made to characterize the involvement of protein-coding genes in ESCC tumorigenesis but few for long noncoding RNAs (lncRNAs). To investigate the transcriptome profile and functional relevance of lncRNAs, we performed an integrative analysis of a customized combined lncRNA-mRNA microarray and RNA-seq data on ESCCs and matched normal tissues. We identified numerous lncRNAs that were differentially expressed between the normal and tumor tissues, termed "ESCC-associated lncRNAs (ESCALs)", of which, the majority displayed restricted expression pattern. Also, a subset of ESCALs appeared to be associated with ESCC patient survival. Gene set enrichment analysis (GSEA) further suggested that over half of the ESCALs were positively- or nelgativelyassociated with metastasis. Among these, we identified a novel nuclear-retained lncRNA, named Epist, which is generally highly expressed in esophagus, and which is down-regulated during ESCC progression. Epist over-expression and knockdown studies further suggest that Epist inhibits the metastasis, acting as a tumor suppressor in ESCC. Collectively, our analysis of the ESCC transcriptome identified the potential tumor suppressing lncRNA Epist, and provided a foundation for future efforts to identify functional lncRNAs for cancerous therapeutic targeting.
分类: 生物学 >> 生物物理学 >> 生物物理、生物化学与分子生物学 提交时间: 2016-05-11
摘要: ERp44, an endoplasmic reticulum (ER) resident protein, regulates intracellular Ca2+ release and involves in the maturation of many proteins in mammalian cells. In this study, we investigated the effects and mechanism of ERp44 on cell apoptosis by using ERp44 knockdown stable HeLa cell lines. We found that ERp44 knockdown resulted in increases in cell apoptosis rate more than one fold higher than that of control; using serum starvation, caspase-3 protein level was significantly up-regulated in ERp44 knockdown cells compared to the control cells. Furthermore, we demonstrated that in response to serum starvation, the protein levels of CHOP and GRP78 were also largely raised in ERp44 knockdown cells. Moreover, caspase-12 was activated, which suggested cell apoptosis was induced by ER stress. Taken together, our results indicate that knockdown of ERp44 leads to cell apoptosis through the activation of ER stress. (C) 2015 Elsevier Inc. All rights reserved.
分类: 生物学 >> 生物物理学 提交时间: 2016-05-11
摘要: Ebola continues to rage in West Africa. In the absence of an approved vaccine or treatment, the priority in controlling this epidemic is to promptly identify and isolate infected individuals. To this end, a rapid, highly sensitive, and easy-to-use test for Ebola diagnosis is urgently needed. Here, by using Fe3O4 magnetic nanoparticle (MNP) as a nanozyme probe, we developed a MNP-based immunochromatographic strip (Nanozyme-strip), which detects the glycoprotein of Ebola virus (EBOV) as low as 1 ng/mL, which is 100-fold more sensitive than the standard strip method. The sensitivity of the Nanozyme-strip for EBOV detection and diagnostic accuracy for New Bunyavirus clinical samples is comparable with ELISA, but is much faster (within 30 min) and simpler (without need of specialist facilities). The results demonstrate that the Nanozyme-strip test can rapidly and sensitively detect EBOV, providing a valuable simple screening tool for diagnosis of infection in Ebola-stricken areas. (C) 2015 Elsevier B.V. All rights reserved.