Abstract:Tumor cells can derive a variety of mechanisms to resist immune defense or drug action. Recent studies have demonstrated that exosomes can mediate cancer progression and distal metastasis. Importantly, exosome plays an important role in regulating DC, macrophages, T cells, NK cells and so on in the microenvironment of tumors. Moreover, exosome can help tumor cells escape the recognition of immune cells by promoting the functions of immunosuppressive cells, such as MDSC and Treg. This review will summarize the role of exosome and its key mediators in mediating tumor immune escape and immune tolerance, and review the latest progress in this field.

Abstract:Runaway mutations cause tumors, some of the non-synonymous mutational (i.e., missense, frameshift, fusion) peptides are degraded into short peptides by proteasome, then APCs (antigen-presenting cells) recognize and present them to draining lymph nodes. These short peptides, in line with the combination of MHC (major histocompatibility complex) motif, are captured by the T cell surface factors and produce an immune response, eventually lead to tumor regression. We call these peptides neoantigens, because these antigens are not negatively screened by thymus gland, they are recognized as "alien" by T cells and are not susceptible to immune tolerance mechanism. Neoantigens can act as effective targets for immune-mediated tumor control. The next generation sequencing technology greatly boosts the feasibility of neoantigen vaccine design, however identifying tumor somatic mutations that can be presented and recognized by TCR (T-cell receptor) is a very demanding yet key step. Many of the predicted "positive" neoantigen peptides are actually "false" and need to be eliminated in further steps to clinical application. Therefore effective screening method is an indispensable part of neoantigen vaccine therapy. However, no related reports have been seen in domestic. In this paper, the computational prediction process of screening methods for potential neoantigen peptides are reviewed.

Abstract:Alzheimer"s disease (AD) is a neurodegenerative disease, which is a serious threat to human health. Epidemiological studies show that the females are related to the higher risk of AD incidence. Therefore, it is of great significance to explore the regularity and characteristics of AD in view of gender difference in AD pathogenesis. This article summarizes the sex difference in the pathogenesis of AD and the related factors involved in sex-dependent AD incidence, and discusses the progress of the research on the prevention and treatment of AD based on the gender difference, hopefully providing new approach for AD therapy.

Abstract:Depression is a common mental illness. Currently, there is no effective way to treat depression. Oxytocin (OT) is a neuropeptide secreted by the paraventricular nucleus and the supraoptic nucleus neurons in the hypothalamus. OT is involved in a variety of complex neuropsychiatric activities under physiological and pathological conditions. In recent years, many clinical and basic studies have shown that OT can relieve depressive symptoms through multiple mechanisms. This article reviews the research progress of the physiological role of OT, the level of OT secretion in depression, the effect of OT on depression-related hormones, brain regions, neural plasticity and oxidative stress. Our review highlights the potential administration of OT in the treatment of depression.

Abstract:Neutrophil recruitment/infiltration is a characteristic manifestation of pulmonary inflammatory diseases and is the first line of defense against pathogenic microbial invasion in the lungs, killing pathogenic microorganisms mainly through phagocytosis. However, new research has found that neutrophils can form a network called neutrophil extracellular traps (NETs) that are DNA-based and inlaid with a large amount of active protein. This biological structure can capture and kill pathogenic microorganisms. Although it is beneficial for lung inflammatory diseases in terms of the biological function of NETs, more and more studies have shown that NETs have direct cytotoxic effects on lung epithelial cells and endothelial cells, and may promote the lung inflammatory diseases. In order to systematically understand the relationship between NETs and lung-related inflammatory diseases, this review first briefly describes the structure, function and formation process of NETs, and then describes the relationship of NETs and asthma, chronic obstructive pulmonary disease, bacterial pneumonia, tuberculosis, cystic fibrosis, interstitial lung disease, influenza virus infection and acute lung injury, finally summarizes the potential research directions and targeted treatment strategies of NETs in pulmonary inflammatory diseases.

Abstract:Adenylate cyclase Ⅲ (AC3) is an important component of odorant perception signaling in the olfactory system. The thinness of main olfactory epithelium (MOE) become thin with ageing, and the gene expression profile alters after AC3 deletion. DNA methylation plays a key role in animal development and regulation of gene expression. In the present study, whether the DNA methylation level of gene promoter, as well as their associations with the expression of the genes in MOE will be altered after AC3 deletion, was investigated by using methylated DNA immunoprecipitation chip (MeDIP-chip), methylation-specific PCR (MSP) and real-time fluorescence quantification PCR. The data showed that the DNA methylation levels of promoters of 1 978 genes were altered in AC3-deficient mice, accounting for 9% of the total number of genes. Of which 727 genes with their promoter’s DNA methylation levels were elevated, 1 251 genes with their promoter’s methylation levels were lowered. The functions of these genes are mainly involved with olfactory receptor, neurodevelopmental, cAMP signaling pathway, ATP-binding, calcium regulation, acetylation modification, and transcription factors. It was further confirmed by MSP that methylation levels of promoter of the olfactory receptor genes Olfr1153, Olfr231, Olfr378, Olfr651 and Olfr691 were increased, whereas methylation level of the promoters of Cngb1, Pde4a and Olfr1394 were decreased. In line with MSP results, qRT-PCR data showed that the expression levels of Cngb1, Hcn4, Olfm1, Olfr1394, Olfr1153, Olfr231, Olfr378 and Olfr691 were significantly decreased, whereas the expression levels of Pde4a and Olfr651 were significantly increased. In conclusion, the methylation levels of promoters of olfactory receptor genes, neurodevelopmental related genes and cAMP signaling pathways in MOE are modified significantly after AC3 deletion, which affected the transduction of signal pathways such as nucleotide excision and repair, DNA replication and mismatch repair, thus comprehensively regulating the number and level of gene expression in MOE of mice.

Abstract:Regulation of cell proliferation is essential for controlling organ size and maintenance of tissue homeostasis in adult organisms. Growth inhibition, termed as “contact inhibition”, in a cell-density dependent manner was common in vitro culture. In this study, the effect of glycosphingolipid GM1 on the contact inhibition of human mammary epithelial cell lines MCF-10A, human breast cancer cell lines BT-549 and SK-BR-3 were investigated. Changes of cell proliferation of MCF-10A, BT-549 and SK-BR-3 cells at low and high cell density was explored. Expression of GM1 in different cell density was detected by flow cytometry. Exogenous GM1 at different cell density was added to explore the effect on cell proliferation. B3GALT4, the GM1 synthase, was knocked down or overexpressed in BT-549 and SK-BR-3 cells by using lentiviral vectors. Then, proliferating ability were tested by cell counting and related pathways was assayed by Western blot, in stable-transfected cell lines. Results showed cell proliferation was inhibited and GM1 expression increased at low and high cell density compared with normal density. Exogenous addition of GM1 at low and high density cells inhibited cell growth, but it had no influence on cell growth at normal density. Down regulation of GM1 promoted cell proliferation at low and high cell density, and overexpression of GM1 had the opposite effect. Together, these results indicate that GM1 inhibit MCF-10A, BT-549 and SK-BR-3 cells proliferation at low and high cell density in vitro, which may potentially provide the experimental basis for further research on its molecular mechanisms.

Abstract:High-accuracy splice site recognition based on machine learning is the key to eukaryotic genome annotation. In this paper, we used chi-square test to determine the window size of sequences, and constructed a chi-square statistical difference table to extract the positional features, and combined with the frequencies of dinucleotides to characterize sequences. For the problem that the positive and negative samples of splice sites are extremely imbalanced, 10 SVM classifiers based on the equal proportion of positive and negative samples were built for weighted voting, which effectively solved the imbalanced pattern classification problem. Independent testing results in HS³D dataset showed that the prediction accuracy of donor and acceptor sites were 93.39% and 90.46% respectively, obviously higher than that of the compared methods. The positional features based on the chi-square statistical difference table can effectively characterize DNA sequences, and have application prospects in signal site recognition of molecular sequences.

Abstract:To investigate the anti-inflammatory effect and mechanism of proper concentration of short-chain fatty acids (SCFAs) mixture (SCFAs mix) on microglia under inflammatory environment. In this study, the murine microglial cell line BV-2 treated with lipopolysaccharide (LPS) was used as an inflammatory cell model. BV-2 cells were treated with different concentrations of sodium acetate, sodium propionate and sodium butyrate, and SCFAs mix, the cell viability were detected by CCK8 kit. The concentrations of each SCFA and SCFAs mixture (SCFAs mix) will be selected by double standard: having no effect on cell viability and having the anti-inflammation effect. The examination of anti-inflammation effect and its mechanism of SCFAs mix in proper concentration on LPS-stimulated BV-2 cells include: (a) the production of NO of BV-2 cells was detected by NO kit, (b) the inflammatory factors such as TNF-α and IL-6 released into the culture supernatant by BV-2 cells were detected by ELISA, (c) the expression of inflammatory factors such as TNF-α and IL-6, inflammasome NLRP3 and some key factors within inflammatory pathways such as TLR4 and NF-κB, were detected by qRT-PCR and Western-blot. We found that after 4 hours of LPS stimulation on BV-2 cells, the addition of a certain concentration of single SCFA to the system for 12 h could not alleviate the inflammatory response of BV-2 cells, but SCFAs mix with the same terminal concentration of each SCFAs could significantly reduce the levels of NO (P<0.001), TNF-α (P<0.001) and IL-6 (P<0.001) in cell culture supernatants. Simultaneously, SCFAs mix inhibited the increase of iNOS, TNF-α, IL-6 (P<0.001) and inflammasome NLRP3 (P<0.001) mRNA in BV-2 cells induced by LPS. Further study showed that SCFAs mix could inhibit LPS-induced high expression of TLR4, MyD88, TRAF6 and NF-κB proteins, which were the key molecules of the inflammatory signaling pathway in BV-2 cells. In conclusion, proper concentration of SCFAs mix could function as a protective role to inhibit LPS-induced microglial inflammatory responses by regulation of the TLR4/MyD88/TRAF6/NF-κB signaling pathway.

Abstract:Thymosin-α1 (Tα1), as a commercial peptide drug, has been chemically synthesized and widely used for enhancing immune responses and anti-tumor. The increasing therapeutic Tα1 need leads to concerns about its mass and low-cost production processes. To prepare peptide thymosin-α1 by a novel recombination expression and purification technique. The thymosin-α1 was designed into a tetraploid concatemer by genetic manipulation and expressed in E. coli, and the purified concatemer thymosin α1 was obtained by one-step heating. Subsequently, the concatemer thymosin-α1 was cleaved into monomers with cyanogen bromide dissolved in 50%-70% trifluoroacetic acid. The thymosin-α1 monomer was further purified by high performance liquid chromatography with purity ≥ 98%. Finally, the obtained thymosin-α1 could stimulate lymphocyte proliferation, which was almost as effective as the commercial thymosin-α1 (Zadaxin?).Finally, The recombinant thymosin-α1 was successfully obtained, which is similar to the commercial one, by genetic recombination, heat purification and appropriate cleavage.