1.A COMPARISON OF THE EFFICIENCY OF DENSITY GRADIENT AND LOW-SPEED CENTRIFUGATION METHODS FOR ISOLATING PLASMODIUM SPOROZOITES
Quanzhen LI ; Xingxiang WANG ; Zhiqiang CHEN
Chinese Journal of Parasitology and Parasitic Diseases 1987;0(03):-
P. yoelii sporozoites(Sp) in Anopheles stephensi were first isolated with low-speed centrifugation and the Sp suspension was subsequantly purified with the density gradient centrifugation. The recovery rates of Sp by the latter method is about 50-75% of that by the former, but few debris could be found in the Sp suspension and the infectivity of the Sp was not weakened as compared with the Sp obtained by low-speed method. Sp would retain partial infectivity, when its suspension was maintained ia medium 199 at 4℃ for 48 hrs. When rats and mice were infected with these Sp, patho-logical changes of hepatocytes such as cloudy swelling or fatty degeneration, which had been evidenced to be induced by mosquito tissues, would be absent or present in th& slightest degree.
2.Antibody-based gene expression profiling of peripheral blood from patients with idiopathic inflammatory myopathy
Muyuan LI ; Li WANG ; Quanzhen LI ; Hui LUO ; Huali ZHANG
Chinese Journal of Rheumatology 2024;28(1):15-21
Objective:To elucidate the pathophysiological mechanisms of idiopathic inflammatory myopathy subtypes by analyzing the gene expression profiles of peripheral blood mononuclear cells (PBMCs) from anti-MDA5 antibody-positive and anti-Jo-1 antibody-positive myositis patients.Methods:Gene expression profiling screening and analysis of PBMCs from 12 anti-MDA5 positive, 16 anti-Jo-1 positive myositis patients and 43 healthy controls were performed using Illumina HT-12 v4 expression profiling microarrays. Applying the unpaired t test with Benjamini-Hochberg correction, the genes with the absolute value of fold change (FC) in gene expression signal ≥2 and adjusted P<0.05 were selected as differentially expressed genes. Differential gene sets were subjected to Gene Ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, with P<0.05 as the threshold for being significantly enriched. Validation of differentially expressed genes by real time-PCR. The Kolmogorov-Smirnov test was used to test the normality of continuous variables. If the distribution was normal and the variance was homogeneous, analysis of variance (one-way ANOVA) was used.If the distribution was not normal, Kruskal-Wallis test was used, and P<0.05 was regarded as statistically significant difference. Results:Analysis of gene expression profiles of PBMCs from patients with positive anti-MDA5 and anti-Jo-1 antibody revealed significant differences in gene expression of PBMCs from patients with the two myositis subtypes. The number of differentially expressed genes that specifically up-regulated in anti-MDA5 antibody positive patients was 407, and the GO functional enrichment analysis was mainly enriched in biological processes such as innate immune response ( P<0.001), response to virus ( P<0.001) and type Ⅰ interferon signaling pathway ( P<0.001), and the KEGG pathway enrichment analysis was mainly enriched in the viral infection-associated pathway ( P<0.001), RIG-Ⅰ like receptor signaling pathway ( P<0.001) and Toll-like receptor signaling pathway ( P=0.002), etc. The 259 differential genes specifically down-regulated in the anti-MDA5 antibody positive group were mainly enriched in biological processes such as immune response ( P=0.006), TGF-β receptor signaling pathway ( P=0.010) and natural killer cell mediated immunity ( P=0.015) in GO functional enrichment analysis. There were 162 differentially expressed genes up-regulated specifically in anti-Jo-1 antibody positive patients, and GO functional enrichment analysis was mainly enriched in biological processes such as nucleosome assembly ( P<0.001), negative regulation of cell growth ( P=0.001), negative regulation of apoptotic process P=0.004), and innate immune response in mucosa ( P=0.012), and the KEGG pathway enrichment analysis mainly enriched in metabolic-related signaling pathways ( P<0.001) and immune-related pathways ( P<0.001), etc. Real-time PCR confirmed that IFIH1 ( P=0.037), ISG15 ( P=0.003), and DDX58 ( P=0.032) in the RIG-Ⅰ-like receptor pathway as well as chemokines MCP-1 ( P=0.003), MCP-2 ( P<0.001), and transcription factor BATF2 ( P=0.002), and inflammatory signaling pathway-associated MYD88 ( P<0.001) were highly expressed in PBMCs from anti-MDA5 antibody-positive myositis patients. Conclusion:The gene expression profile of PBMCs in anti-MDA5 antibody-positive patients suggests that the pathogenesis of patients with anti-MDA 5 antibody positive is closely related to biological processes such as innate immune response, viral infection, and interferon response.
3.Expression, purification and immunoreactivity characterization of extracellular antigenic domains of NMDAR1 protein.
Ding BAO ; Wei LI ; Leming SHI ; Quanzhen LI
Chinese Journal of Biotechnology 2017;33(12):1979-1988
This study aimed to construct prokaryotic recombinant plasmids for expression of the extracellular domains of NMDAR1 protein, purify and characterize the immunoreactivity of the recombinant proteins. Based on the mRNA sequence of human NMDAR1 gene, we predicted the structure of the antigenic domains in the extracellular part of the protein using the "phyre2" software. Primers were designed to amplify the nucleic acid fragments encoding the NMDAR1 extracellular antigenic domains by RT-PCR. The amplified gene fragments were cloned into pCold-SUMO vector to construct the recombinant plasmids which were transformed into Escherichia coli DH5α. The positive colonies harboring the recombinant plasmids were picked and verified by PCR and DNA sequencing. Then, the recombinant plasmids were transformed into E. coli BL21(DE3) strain and induced by IPTG for protein expression. The recombinant proteins were purified by Ni-NTA affinity chromatography. The target proteins were further purified by removing the 6 His-SUMO tag using enzyme excision followed by gel filtration chromatography using AKTA purifier. The purity of the recombinant proteins were evaluated by SDS-PAGE and the immunoreactivity were characterized by Western blotting. Three DNA fragments encoding the extracellular domains of NMDAR1 protein, including NR1-M1 (encoding 19-393 aa), NR1-S1 (encoding 394-544 aa) and NR1-S2 (encoding 663-800 aa), were amplified by RT-PCR. The NR1-S1 and NR1-S2 were linked with G (arginine) and T (threonine) amino acid as a combined fragment. The NR1-M1 and NR1-S1-GT-S2 fragments were cloned into pCold-SUMO vector and two recombinant plasmids, pCold-SUMO-M1 and pCold-SUMO-S1-GT-S2, were generated and expressed in E. coli. SDS-PAGE analysis showed that the recombinant plasmids expressed soluble NR1-M1 and NR1-S1-GT-S2 proteins in bacterial. After affinity chromatography and gel filtration chromatography, we obtained high purity target proteins. Western blotting assay showed that the recombinant proteins NR1-M1 and NR1-S1-GT-S2 can bind specially with their corresponding antibodies, suggesting the recombinant proteins retained antigenic reactivity. We constructed a prokaryotic expression system for expressing the NMDAR1 protein extracellular parts that had immunoreactivity successfully, and the purified proteins can be used for studying NMDAR1 function and testing the autoantibodies.
4.Genome-wide DNA methylation and transcriptome expression profiles of peripheral blood mononuclear cells in patients with systemic sclerosis with interstitial lung disease.
Yanli XIE ; Hongjun ZHAO ; Hui LUO ; Xiaoxia ZUO ; Quanzhen LI ; Sijia LIU
Journal of Central South University(Medical Sciences) 2023;48(6):829-836
OBJECTIVES:
This study aims to investigate the genome-wide DNA methylation and transcriptome expression profiles of peripheral blood mononuclear cells (PBMCs) in patients with systemic sclerosis (SSc) with interstitial lung disease (ILD), and to analyze the effects of DNA methylation on Wnt/β-catenin and chemokine signaling pathways.
METHODS:
PBMCs were collected from 19 patients with SSc (SSc group) and 18 healthy persons (control group). Among SSc patients, there were 10 patients with ILD (SSc with ILD subgroup) and 9 patients without ILD (SSc without ILD subgroup). The genome-wide DNA methylation and gene expression level were analyzed by using Illumina 450K methylation chip and Illumina HT-12 v4.0 gene expression profiling chip. The effect of DNA methylation on Wnt/β-catenin and chemokine signal pathways was investigated.
RESULTS:
Genome-wide DNA methylation analysis identified 71 hypermethylated CpG sites and 98 hypomethylated CpG sites in the SSc with ILD subgroup compared with the SSc without ILD subgroup. Transcriptome analysis distinguished 164 upregulated genes and 191 downregulated genes in the SSc with ILD subgroup as compared with the SSc without ILD subgroup. In PBMCs of the SSc group, 35 genes in Wnt/β-catenin signaling pathway were hypomethylated, while frizzled-1 (FZD1), mitogen-activated protein kinase 9 (MAPK9), mothers against DPP homolog 2 (SMAD2), transcription factor 7-like 2 (TCF7L2), and wingless-type MMTV integration site family, member 5B (WNT5B) mRNA expressions were upregulated as compared with the control group (all P<0.05). Compared with the SSc without ILD subgroup, the mRNA expressions of dickkopf homolog 2 (DKK2), FZD1, MAPK9 were upregulated in the SSc with ILD subgroup, but the differences were not statistically significant (all P>0.05). In PBMCs of the SSc group, 38 genes in chemokine signaling pathway were hypomethylated, while β-arrestin 1 (ARRB1), C-X-C motif chemokine ligand 10 (CXCL10), C-X-C motif chemokine ligand 16 (CXCL16), FGR, and neutrophil cytosolic factor 1C (NCF1C) mRNA expressions were upregulated as compared with the control group (all P<0.05). Compared with the SSc without ILD subgroup, the mRNA expressions of ARRB1, CXCL10, CXCL16 were upregulated in the SSc with ILD subgroup, but the differences were not statistically significant (all P>0.05).
CONCLUSIONS
There are differences in DNA methylation and transcriptome profiles between SSc with ILD and SSc without ILD. The expression levels of multiple genes in Wnt/β- catenin and chemokine signaling pathways are upregulated, which might be associatea with the pathogenesis of SSc.
Humans
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DNA Methylation
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Transcriptome
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beta Catenin
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Leukocytes, Mononuclear
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Ligands
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DNA
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RNA, Messenger/genetics*