Inhibition of A2AR gene methylation alleviates white matter lesions in chronic cerebral hypoperfusion rats.

OBJECTIVE: Chronic cerebral hypoperfusion (CCH) can cause ischemic cerebral white matter lesions (IWML). The aim of this study was to explore the roles of A2A receptors (A2AR) in IWML and the effect of methylation in A2AR gene. MATERIALS AND METHODS: SD rat model of CCH was constructed by bilateral common carotid artery occlusion (BCCAO) method. The rats were then treated with DNA methyltransferase (DNMT) inhibitor (decitabine), agonist (CGS21680) and A2AR inhibitor (SCH58261). Morris water maze and Kluver-Barrera staining were used to assess spatial learning and reference memory after IWML, respectively. Gene transcription and protein expression were measured by qRT-PCR, Enzyme-linked immunosorbent assay (ELISA) and Western blotting, respectively. The concentration of malondialdehyde (MDA), activity of superoxide dismutase (SOD) and DNMT were detected by assay kit. Methylation of A2AR gene promoter region was detected by bisulfite sequencing PCR (BSP). RESULTS: We found that the down-regulated expression of A2AR in corpus callosum under CCH was associated with IWML and cognitive impairment. We further showed that A2AR agonist can reduce the IWML under CCH, and A2AR inhibitor can aggravate the IWML under CCH. We also found that the expression level of DNMTs in corpus callosum and the methylation level in the promoter region of A2AR gene were increased under CCH. DNMT inhibitors could protect white matter by inhibiting the methylation of A2AR promoter and rescue the downregulation of A2AR under CCH. CONCLUSIONS: Our results demonstrate that the downregulation of A2AR mediates IWML in CCH, and A2AR downregulation is related to the increased methylation of A2AR gene promoter. DNMT inhibitors play a protective role in IWML.

RNA-seq reveals transcriptome changes of the embryonic lens cells in Prox1 tissue specific knockout mice.

OBJECTIVE: Prox1 is expressed in both lens epithelial cells and fiber cells and is essential for lens fiber cell elongation. This study aimed to explore the molecular mechanisms of how Prox1 mutations influence lens fiber cells development. MATERIALS AND METHODS: Comparative transcriptomes analysis of Prox1 conditional knockout (cKO) lens and wild-type (WT) lens were performed using the data GSE69940 downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were determined by the R package "edgeR" of Trinity software. GO (Gene Ontology) enrichment analysis and KEGG (Kyoto Encyclopedia of Genes and Genomes databases) enrichment analysis were performed using the cluster Profiler R package. Then, the protein-protein interaction (PPI) network was predicted using Cytoscape, and the Module analysis of the PPI network was analyzed through the Cytoscape MCODE plugin. Moreover, MotifDb package in R was used to predict the transcription factors binding to Prox1 promoter regions. RESULTS: In total, 2263 differentially expressed genes were identified between the two groups. GO and KEGG analysis showed that the down-regulated genes were enriched in camera-type eye term, nucleosome assembly, lens fiber cell differentiation, and cell modified and amino acid metabolism. The KEGG pathway of up-regulated genes was associated with lens development, including Hedgehog signaling pathway and MAPK signaling pathway. GO terms of up-regulated DEGs were mainly relevant to bone morphological development, muscle development, and sensory organ morphological development. Next, the PPI network of DEGs was constructed, and 4 modules were analyzed. Moreover, 30 transcription factors were predicted, which are likely to be downstream targets of Prox1 with potential roles in lens development in mice. CONCLUSIONS: This study provides insights into the unique transcriptome profile of lens cells in Prox1 conditional knockout mice, which is a valuable resource for further study of mouse lens genomics.

Cloning of an anthocyanidin synthase gene homolog from blackcurrant (Ribes nigrum L.) and its expression at different fruit stages.

Anthocyanidin synthase (ANS), a 2-oxoglutarate (2OG) and Fe(II)-dependent oxygenase, catalyzes the penultimate step in anthocyanin biosynthesis, from leucoanthocyanidins to anthocyanidins, the first colored compound in the anthocyanin pathway. In this study, a full-length, 1427-bp long cDNA named RnANS1, which is homologous to the anthocyanidin synthase gene, was cloned from blackcurrant using a homologous cloning strategy. RnANS1 is highly homologous to other plant ANS genes at both the nucleotide and amino acid sequence levels. The deduced protein contains domains conserved in the 2OG and Fe(II)-dependent oxygenase, and is phylogenetically closely related to Paeonia suffruticosa and Paeonia lactiflora. The expression of RnANS1 was upregulated during fruit maturation, and correlated with the accumulation of anthocyanins and soluble carbohydrates in the fruit. Further characterization of the structure and expression patterns of RnANS1 will clarify our understanding of anthocyanin biosynthesis in blackcurrant, and support the development of molecular approaches to manipulate anthocyanin production in this plant.

Intranasal immunisation with Stx2B-Tir-Stx1B-Zot protein leads to decreased shedding in goats after challenge with Escherichia coli O157:H7.

Ruminants are an important reservoir of Escherichia coli O157:H7. To reduce E coli O157:H7 excretion by these animals could play a key role in prevention and control of human infections. In the present study, the authors used 12 three-month-old goats to evaluate the efficacy of intranasal administration of the Stx2B-Tir-Stx1B-Zot protein. These goats were inoculated on days 0 and 21 and infected with 10(10) colony-forming units (cfu) of E coli O157:H7 by oral inoculation on day 36. Faecal shedding was monitored daily for two weeks. All of six goats immunised with recombinant protein elicited significant Stx2b-Tir-Stx1b-Zot-specific serum IgG antibodies, and three of them also showed production of antigen-specific IgA in faeces. The immunised goats showed much less shedding of E coli O157:H7 after challenge. These results demonstrate the potential for the use of Stx2B-Tir-Stx1B-Zot protein in mucosal vaccine formulations to prevent colonisation and shedding of E coli O157:H7 in goats.

TNIP1, SLC15A4, ETS1, RasGRP3 and IKZF1 are associated with clinical features of systemic lupus erythematosus in a Chinese Han population.

Systemic lupus erythematosus (SLE) is an autoimmune disease with heterogeneous clinical manifestations influenced by genetic and environmental factors. Five novel susceptibility genes (TNIP1, SLC15A4, ETS1, RasGRP3 and IKZF1) for SLE have been identified in a recent genome-wide association study of a Chinese Han population. This study investigated their relationships with disease subphenotypes, including renal nephritis, photosensitivity, antinuclear antibody (ANA), age at diagnosis, malar rash, discoid rash, immunological disorder, oral ulcer, hematological disorder, neurological disorder, serositis, arthritis and vasculitis. Significant associations were found for the single nucleotide polymorphism rs10036748 of TNIP1 with photosensitivity (odds ratio (OR) = 0.87, p = 0.01) and vasculitis (OR = 1.18, p = 0.04); rs10847697 of SLC15A4 with discoid rash (OR = 1.18, p = 0.02); rs6590330 of ETS1 with SLE of age at diagnosis <20 years (OR = 1.24, p = 8.91 x 10(-5)); rs13385731 of RasGRP3 with malar rash (OR = 1.20, p = 0.01), discoid rash (OR = 0.78, p = 0.02) and ANA (OR = 0.72, p = 0.004); rs4917014 of IKZF1 with renal nephritis (OR = 1.13, p = 0.02) and malar rash (OR = 0.83, p = 0.00038), respectively. The study suggested that these susceptibility genes might not only play important roles in the development of SLE, but also contribute to the complex phenotypes of SLE.

The effect of Malononitrilamides (FK778) on phenotypic properties of human peripheral dendritic cells.

BACKGROUND: FK778, a malononitrilamide analogue of lefunomide, is currently a promising immunosuppressive drug. Because the cellular and molecular mechanisms underlying the effects of FK778 are not entirely clarified. We studied its effects on human peripheral dendritic cells. METHODS: Peripheral blood mononuclear cells (PBMC) from 12 healthy volunteers were isolated by density separation over Ficoll solution. After resuspension in adaptive immunotherapy medium (AIM)-V medium, they were cultured without exogenous growth factors. The study group was treated with FK 778 (50 microg/mL) or Rapamycin (10 ng/mL). The phenotype of dendritic cell was ascertained by indirect immunoflurescence for analysis by flow cytometry. RESULTS: Compared with the Rapamycin-treated controls, the expressions of CD80, CD83, CD86, HLA-DA, CD54, CD62, CCR5, and CCR7 in the FK778-treated myeloid dendritic cells and the expression of CD80, CD83, CD86, HLA-DA, and CD54 in the FK778-treated plasmacytoid dendritic cells were significantly down-regulated. CONCLUSION: FK778 inhibited the differentiation and maturation of dendritic cells.

Pennogenin glycosides with a spirostanol structure are strong platelet agonists: structural requirement for activity and mode of platelet agonist synergism.

BACKGROUND: Steroidal saponins have long attracted scientific attention, due to their structural diversity and significant biological activities. For example, total steroidal saponins extracted from the rhizome of Paris polyphylla Sm. var. yunnanensis (TSSPs) constitute an effective treatment for abnormal uterine bleeding. OBJECTIVE: To determine the active constituents in TSSPs and elucidate the mechanisms that underlie their in vivo pharmacologic actions on hemostasis. METHODS: Steroidal saponins were purified by chromatography, and their effects upon hemostasis and platelet function were evaluated by tail bleeding time in mice and rats, aggregometry, flow cytometry and Western blotting. RESULTS: TSSPs promoted hemostasis in vivo and dose-dependently induced rat or human platelet aggregation in vitro. Using bioassay-guided separation, four known pennogenin glycosides with a spirostanol structure were identified as the active ingredients of TSSPs. A structure-activity assay showed that the aglycone and sugar moieties of pennogenin glycosides are both essential for their aggregatory activity. Their synergistic actions on platelet aggregation were observed with pennogenin glycosides and with other known platelet agonists, suggesting that these glycosides are platelet agonists. Aggregation in response to the pennogenin glycosides involved alpha(IIb)beta(3) activation, was inhibited by cAMP, was dependent upon extracellular calcium, secreted ADP and thromboxane synthesis, and was mediated by phosphatidylinositol-3-kinase. CONCLUSION: We identified pennogenin glycosides with a spirostanol structure as the active ingredients of Paris polyphylla Sm. var. yunnanensis in promoting hemostasis in vivo. Their mode of their action on platelets suggests that they represent a new type of platelet agonist.

Protein-protein interactions involving inducible nitric oxide synthase.

AIM: Nitric oxide (NO) is a signaling and effector molecule that contributes to multiple physiological and pathophysiological processes in the kidney, vasculature, and other tissues. High output NO generation by inducible NO synthase (iNOS) participates in host defense against pathogens and contributes to tissue injury during inflammatory states. Because of its potent reactivity and diffusibility, NO generation by iNOS is subject to multiple levels of regulation, including transcriptional, translational, and post-translational controls, including protein-protein interactions. This review examines the experimental basis for these protein-protein interactions and their known and potential importance for kidney and vascular physiology. METHODS: Analysis of the biomedical literature in the area. RESULTS: iNOS interacts with the inhibitory molecules Kalirin and NOS-associated protein 1.10 kd (NAP110), which inhibit iNOS homodimerization, as well as activator proteins, the Rac-GTPases. Interactions with caveolin-1 control the intracellular locale and degradation of iNOS in tumor cells. In polarized epithelial cells, associations of iNOS with the scaffolding protein EBP50 position iNOS in the apical membrane near key ion transport proteins that also interact with EPB50. In addition, protein-protein interactions of proteins governing iNOS transcription function to specify activation or suppression of iNOS induction by cytokines. CONCLUSION: Interactions of iNOS with a diverse group of heterologous proteins provides a selective mechanism to control the activity, spatial distribution, and proximity of iNOS to intended targets, while potentially limiting autotoxicity to the iNOS-expressing cell.