Mechanisms of brain damage caused by inorganic fluoride using proteomics-based techniques / 环境与职业医学

Background Chronic excessive exposure to fluoride can cause damage to the central nervous system and a certain degree of learning and memory impairment. However, the associated mechanism is not yet clear and further exploration is needed. Objective Using 4D unlabelled quantitative proteomics techniques to explore differentially expressed proteins and their potential mechanisms of action in chronic excessive fluoride exposure induced brain injury. Methods Twenty-four SPF-grade adult SD rats, half male and half male, were selected and divided into a control group and a fluoride group by random number table method, with 12 rats in each group. Among them, the control group drank tap water (fluorine content<1 mg·L−1), the fluoride group drank sodium fluoride solution (fluorine content 10 mg·L−1), and both groups were fed with ordinary mouse feed (fluoride content<0.6 mg·kg−1). After 180 d of feeding, the SD rats were weighed, and then part of the brain tissue was sampled for pathological examination by hematoxylin-eosin (HE) staining and Nissl staining. The rest of the brain tissue was frozen and stored at −80 ℃. Three brain tissue samples from each group were randomly selected for proteomics detection. Differentially expressed proteins were screened and subcellular localization analysis was performed, followed by Gene Ontology (GO) function analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, cluster analysis, and protein-protein interaction analysis. Finally, Western blotting was used to detect the expression levels of key proteins extracted from the brain tissue samples. Results After 180 d of feeding, the average weight of the rats in the fluoride group was significantly lower than that in the control group (P<0.05). The brain tissue stained with HE showed no significant morphological changes in the cerebral cortex of the fluoride treated rats, and neuron loss, irregular arrangement of neurons, eosinophilic changes, and cell body pyknosis were observed in the hippocampus. The Nissl staining results showed that the staining of neurons in the cerebral cortex and hippocampus of rats exposed to fluoride decreased (Nissl bodies decreased). The proteomics results showed that a total of 6927 proteins were identified. After screening, 206 differentially expressed proteins were obtained between the control group and the fluoride group, including 96 up-regulated proteins and 110 down-regulated proteins. The differential proteins were mainly located in cytoplasm (30.6%), nucleus (27.2%), mitochondria (13.6%), plasma membrane (13.6%), and extracellular domain (11.7%). The GO analysis results showed that differentially expressed proteins mainly participated in biological processes such as iron ion transport, regulation of dopamine neuron differentiation, and negative regulation of respiratory burst in inflammatory response, exercised molecular functions such as ferrous binding, iron oxidase activity, and cytokine activity, and were located in the smooth endoplasmic reticulum membrane, fixed components of the membrane, chloride channel complexes, and other cellular components. The KEGG significantly enriched pathways included biosynthesis of secondary metabolites, carbon metabolism, and microbial metabolism in diverse environments. The results of differential protein-protein interaction analysis showed that the highest connectivity was found in glucose-6-phosphate isomerase (Gpi). The expression level of Gpi in the brain tissue of the rats in the fluoride group was lower than that in the control group by Western blotting (P<0.05). Conclusion Multiple differentially expressed proteins are present in the brain tissue of rats with chronic fluorosis, and their functions are related to biosynthesis of secondary metabolites, carbon metabolism, and microbial metabolism in diverse environments; Gpi may be involved in cerebral neurological damage caused by chronic overdose fluoride exposure.

Preliminary study on differentially expressed proteins in a mouse model of secondary cystic echinococcosis based on data independent acquisition proteomics / 中国血吸虫病防治杂志

Objective To identify the differentially expressed proteins in different liver tissues in the mouse model of cystic echinococcosis (CE), so as to provide insights into the research and development of therapeutic drugs targeting CE. Methods Female Kunming mice at ages of 6 to 8 weeks were randomly assigned into the CE group and the control group. Mice in the CE group were intraperitoneally infected with 2 000 Echinococcus multilocularis protoscoleces, while mice in the control group were injected with the same volume of physiological saline. All mice in both groups were sacrificed after breeding for 350 d, and the lesions (the lesion group) and peri-lesion specimens (the peri-lesion group) were sampled from the liver of mice in the CE group and the normal liver specimens (the normal group) were sampled from mice in the control group for data independent acquisition (DIA) proteomics analysis, and the differentially expressed proteins were subjected to Gene Ontology (GO) term enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Results A total of 26 differentially expressed proteins were identified between the lesion group and the normal group and between the peri-lesion group and the normal group, including 8 up-regulated proteins and 18 down-regulated proteins. GO term enrichment analysis showed that these differentially expressed proteins were predominantly enriched in endoplasmic reticulum membrane (biological components), oxidoreductase activity (molecular function) and oxoacid metabolic process and monocarboxylic acid metabolic process (biological processes). KEGG pathway enrichment analysis revealed that the differentially expressed protein Acyl-CoA oxidase 1 (Acox1), which contributed to primary bile acid biosynthesis during the fatty acid oxidation, was involved in peroxisome signaling pathway, and the differentially expressed protein fatty acid binding protein 1 (Fabp1), which contributed to fatty acid transport, was involved in the peroxisome proliferator-activated receptor (PPAR) signaling pathway. Conclusion Differentially expressed proteins are identified in the liver specimens between mouse models of CE and normal mice, and some differentially expressed proteins may serve as potential drug targets for CE.

Differential proteomic analysis of children infected with respiratory syncytial virus

Respiratory syncytial virus (RSV) infection is the main cause of lower respiratory tract infection in children. However, there is no effective treatment for RSV infection. Here, we aimed to identify potential biomarkers to aid in the treatment of RSV infection. Children in the acute and convalescence phases of RSV infection were recruited and proteomic analysis was performed to identify differentially expressed proteins (DEPs). Subsequently, promising candidate proteins were determined by functional enrichment and protein-protein interaction network analysis, and underwent further validation by western blot both in clinical and mouse model samples. Among the 79 DEPs identified in RSV patient samples, 4 proteins (BPGM, TPI1, PRDX2, and CFL1) were confirmed to be significantly upregulated during RSV infection. Functional analysis showed that BPGM and TPI1 were mainly involved in glycolysis, indicating an association between RSV infection and the glycolysis metabolic pathway. Our findings provide insights into the proteomic profile during RSV infection and indicated that BPGM, TPI1, PRDX2, and CFL1 may be potential therapeutic biomarkers or targets for the treatment of RSV infection.

Investigation of Mechanism of Tryptanthrin Inhibiting Breast Cancer in Mice Based on Proteomics / 中国实验方剂学杂志

Objective:A systematical study on the anti-breast cancer mechanism of tryptanthrin in breast cancer-bearing mice was done by Label-free proteomics. Method:UPLC-MS was used to detect the expressed-proteins of tryptanthrin inhibiting breast cancer in mice， chromatographic separation was achieved on the Ionoptics nano UPLC C18 column （0.075 mm×250 mm， 1.6 μm）， and gradient elution was performed with 0.1% formic acid aqueous solution-0.1% formic acid acetonitrile solution as mobile phase. Data acquisition was carried out in electrospray ionization （ESI） under the positive ion mode， the scanning range was m/z 100-1 700， MaxQuant 1.6.5.0 was used for database retrieval. Label-free proteomics with high resolution mass spectrometry was used to screen differentially expressed proteins between the model group of 4T1 breast cancer mice and oral administration group of tryptanthrin （100 mg·kg-1）. The proteomics of tryptanthrin against breast cancer was carried out. Result:A total of 3 997 proteins were identified in this proteomics research， and 2 911 proteins were quantifiable. A total of 750 differentially expressed proteins were identified between the model group and the tryptanthrin group， 286 proteins were up-regulated and 464 proteins were down-regulated. Gene ontology analysis showed that these differentially expressed proteins were mainly involved in biological processes of proliferation， cell migration， apoptosis， immunity， angiogenesis， inflammatory regulation， etc. Kyoto encyclopedia of genes and genomes pathway analysis further indicated that these proteins were mainly concentrated in T cell receptors， B cell receptors， Toll-like receptors， nuclear transcription factor-κB （NF-κB）， Ras proteins， interleukin-17， tumor necrosis factor， phosphatidylinositol 3-kinase/protein kinase B （PI3K-Akt）， mitogen-activated protein kinase （MAPK） and other signaling pathways. Conclusion:The differentially expressed proteins closely related to anti-breast cancer effect of tryptanthrin on 4T1 breast cancer mice are effectively screened out， including up-regulating proteins of leukocyte differentiation antigen 14 （CD14）， prostaglandin G/H synthase 2 （PTGS2）， E3 ubiquitin-protein ligase and down-regulating proteins of CD44， heat shock 70 kDa protein 1A （HSPA1A）， macrophage migration inhibitory factor （MIF）， NF-κB， ribosomal protein S6 kinase alpha-4 （RPS6KA4） and high mobility group protein B1 （HMGB1）. These findings suggest that tryptanthrin can inhibit breast cancer in mice mainly through regulating tumor inflammatory microenvironment.

TMT proteomics and bioinformatics to analyze protein differences in different Hup A content of thallus of Huperzia serrata / 中草药

Objective: To analyze the differences in protein of thallus of Huperzia serrata (in vitro cultures, strains A, B, and C, respectively) with different Hup A content, and to explore related enzymes that may be synthesized with Hup A accumulation. Methods: Quantitative proteomics was performed in vitro cultures of Huperzia serrata with different Hup A content using quantitative proteomics tandem mass tag (TMT) techniques, followed by differential protein analysis: GO, KEGG and other biological information analysis. Results: Strain B hadthe lowest Hup A content and strain C had the highest Hup A content, which was twice than that of B. There were 78 differential proteins between the strain B and C. Analysis of differential protein GO enrichment showed that MF accounted for 28.75%; Analysis of differential protein expression showed that three strains shared two differential proteins (P93541, Q8RXU4) in the alkaloid metabolic pathway starting from amino acids. P93541 protein was down-regulated in the low-yield strain B and up-regulated in the relatively high-yield strains A and C. The Q8RXU4 protein was up-regulated in the low-yield strain B and down-regulated in the relatively high-yield strains A and C. Conclusion: This study found that the difference in Hup A content was positively correlated with the protein expression. Two enzymes P93541 and Q8RXU4 that may be related to Hup A accumulation were analyzed, providing a basis for bioinformatics analysis of Hup A biosynthesis.

Analysis of differential protein expression profile of HeLa cells stably transfected with Chlamydia trachomatis pORF5 gene / 中华微生物学和免疫学杂志

Objective To analyze the protein expression profile of HeLa cells transfected with pORF5 gene of Chlamydia trachomatis. Methods A lentiviral expression vector containing pORF5 gene was constructed. The lentiviral expression vector and helper plasmids were co-transfected into 293T cells to construct the recombinant lentivirus, which was used to infect HeLa cells. HeLa cells transfected with pORF5 gene and control HeLa cells were sorted out by flow cytometry. The isobaric tags for relative and absolute quantitation ( iTRAQ) approach combined with nano-liquid chromatography-tandem mass spec-trometry ( NanoLC-MS/MS) analysis was performed to understand protein expression profiles and to iden-tify and quantify the differentially expressed proteins in the pORF5-transfected HeLa cells ( pORF5-Hela) and the control HeLa cells. Quantitative real-time PCR ( qRT-PCR ) and Western blot analysis were performed to detect the expression of some proteins at mRNA and protein levels, respectively. Results HeLa cell line stably transfected with pORF5 gene and control HeLa cell line were constructed successful-ly. Totally 314 proteins were differentially expressed between the pORF5-HeLa and control HeLa cells, 159 of which showed increased expression and the other 155 showed decreased expression in pORF5-HeLa cells. The differentially expressed proteins were involved in many processes, such as metabolic process, immune response, biological adhesion and so on. Results of qRT-PCR showed that the expression of HIST1H1C(histone H1. 2C), HBA1(hemoglobin subunit alpha), PARK7(parkinson disease protein 7), HMGB1(high mobility group protein B1) and HMGB2 at mRNA level in pORF5-HeLa cells were up-regulated, while the expression of CLIC1 ( chloride intracellular channel protein 1 ) , KRT7 ( typeⅡ cy-toskeletal 7), SFN(14-3-3 protein sigma) and CDKN2A(cyclin-dependent kinase inhibitor 2A) were down-regulated. Western blot analysis confirmed the enhanced expression of HMGB1 and PRAK7 at pro-tein level. The results of qRT-PCR and Western blot analysis were consistent with proteomic data. Con-clusion Expression profiles for differentially expressed proteins between pORF5-HeLa and control HeLa cells were established successfully. The differentially expressed proteins regulated by pORF5 gene were found to be related to cell metabolism, proliferation, adhesion and so on, suggesting that pORF5 might promote the growth and proliferation of Ct by regulating protein expression and biological behavior of host cells.

Differential proteomic study of papillary thyroid carcinoma and thyroid borderline lesion / 中国肿瘤临床

Objective:To search for potential protein biomarkers of papillary thyroid carcinoma (PTC) and thyroid borderline lesion. Dif-ferentially expressed proteins between the two were analyzed and identified. Methods:A total of 118 cases of thyroid resection sam-ples were obtained from patients who underwent surgery at the First People's Hospital of Yunnan Province from April 2013 to Febru-ary 2015. Experimental groups included 43 PTCs (40 classic and 3 follicular variants) and 33 thyroid borderline lesions (with equivocal PTC type nuclear features and papillary structure, but without metastasis, and lacking capsular or vascular invasion;8 cases with atypi-cal adenoma), respectively. The control group included 42 normal thyroid tissues adjacent to carcinoma. The total protein extracts from frozen thyroid samples of 10 cases in each group were profiled with 2D electrophoresis. The differential protein spots were then revealed by PDQUEST 7.3 software and identified by matrix-assisted laser desorption ionization time-of-fight/time-of-fight mass spec-trometry and Swiss-Prot database search. Six differentially expressed proteins of these spots were further validated using 118 samples through immunohistochemistry. Results:A set of 24 differentially expressed spots significant in discriminating between the sample groups were found, and 18 proteins were identified. Immunohistochemistry revealed the following six proteins located in the cyto-plasm:keratin, type II cytoskeletal 8 (CK8);keratin, type I cytoskeletal 18 (CK18);60 kDa heat shock protein (HSP60);actin, cytoplasmic 2 (γ-actin);14-3-3 protein beta/alpha (14-3-3β/α);and 14-3-3 protein epsilon (14-3-3ε). All six proteins were overexpressed in PTC compared with normal tissues (P<0.001). Meanwhile, CK8, CK18, HSP60, andγ-actin were overexpressed in PTC compared with bor-derline lesions (P<0.01). Except for CK8, the five other proteins were overexpressed in borderline lesions compared with normal tis-sues (P<0.001). Conclusion:Proteomic analysis is useful in searching for new biomarkers of PTC and thyroid borderline lesion. The ex-pression patterns of these differentially expressed proteins can be further validated using immunohistochemistry. The newly identified protein biomarkers can positively contribute to early PTC diagnosis.