ABSTRACT
Nitrogen (N) is one of the most essential mineral elements for plants. Brassinosteroids (BRs) play key roles in plant growth and development. Emerging evidence indicates that BRs participate in the responses to nitrate deficiency. However, the precise molecular mechanism underlying the BR signaling pathway in regulating nitrate deficiency remains largely unknown. The transcription factor BES1 regulates the expression of many genes in response to BRs. Root length, nitrate uptake and N concentration of bes1-D mutants were higher than those of wild-type under nitrate deficiency. BES1 levels strongly increased under low nitrate conditions, especially in the non-phosphorylated (active) form. Furthermore, BES1 directly bound to the promoters of NRT2.1 and NRT2.2 to promote their expression under nitrate deficiency. Taken together, BES1 is a key mediator that links BR signaling under nitrate deficiency by modulating high affinity nitrate transporters in plants.
Subject(s)
Arabidopsis Proteins , Arabidopsis , DNA-Binding Proteins , Arabidopsis/metabolism , Arabidopsis Proteins/metabolism , Brassinosteroids/metabolism , DNA-Binding Proteins/metabolism , Gene Expression Regulation, Plant/genetics , Nitrates/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Anion Transport Proteins/metabolismABSTRACT
A novel actinobacterium, designated strain NEAU-HG-1T, was isolated from soil collected from Harbin, Heilongjiang Province, Northeast China and characterised using a polyphasic approach. On the basis of 16S rRNA gene sequence analysis, strain NEAU-HG-1T belonged to the genus Micromonospora, and shared high sequence similarities with Micromonospora auratinigra DSM 44815T (98.9%) and Micromonospora coerulea DSM 43143T (98.7%). Morphological and chemotaxonomic characteristics of the strain also supported its assignment to the genus Micromonospora. Cell wall contained meso-diaminopimelic acid and the whole-cell sugars were arabinose and xylose. The polar lipid contained diphosphatidylglycerol, phosphatidylethanolamine, glycolipid and phosphatidylinositol. The predominant menaquinones were MK-10(H2), MK-10(H4) and MK-10(H6). The major fatty acids were C17:0 cycle, iso-C15:0, and iso-C16:0. Furthermore, strain NEAU-HG-1T displayed a DNA-DNA relatedness of 33.8 ± 2.2% with M. coerulea DSM 43143T. The level of digital DNA-DNA hybridization between strain NEAU-HG-1T and M. auratinigra DSM 44815T was 27.2% (24.8-29.7%). The value was well below the criteria for species delineation of 70% for dDDH. Whole-genome average nucleotide identity analyses result also indicated that the isolate should be assigned to a new species under the genus Micromonospora. Therefore, it is concluded that strain NEAU-HG-1T represents a novel species of the genus Micromonospora, for which the name Micromonospora rubida sp. nov. is proposed, with NEAU-HG-1T (= CGMCC 4.7479T = JCM 32386T) as the type strain.
Subject(s)
Micromonospora , Bacterial Typing Techniques , DNA, Bacterial/genetics , Fatty Acids/analysis , Micromonospora/genetics , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Soil , Soil Microbiology , Vitamin K 2Subject(s)
Laparoscopy , Proctectomy , Rectal Neoplasms , Female , Pregnancy , Humans , Colpotomy , Surgical Flaps/transplantation , Rectal Neoplasms/surgery , Perineum/surgery , Retrospective StudiesABSTRACT
PURPOSE: To evaluate the effect of the TLR2 (Toll-like receptor 2)/MyD88/NF-κB axis on the allograft rejection after penetrating keratoplasty (PK). METHODS: The PK rat models were randomly divided into four groups: allograft group, dexamethasone group, PDTC group and isograft group. The mean survival time (MST) and rejection index of corneal grafts were observed. The immunohistochemical staining of TGF-α was performed on day 15. The messenger RNA (mRNA) and protein expression of TLR2, MyD88 and NF-κB p65 in corneal grafts were detected by reverse transcription-polymerase chain reaction (RT-PCR) and western blotting. RESULTS: On days 5, 7, 9, 11, 13 and 15, the rejection index in the allograft group was higher than in the other three groups (p < 0.05). The MST in the PDTC group (MST, 23.30 ± 0.42 days, n = 10) and in the dexamethasone group (MST, 24.40 ± 0.50 days, n = 10) were higher than in the allograft group (MST, 14.7 ± 0.70 days, n = 10) (χ(2) = 18.02, p < 0.01; χ(2) = 21.47, p < 0.01). The expression of TNF-α in the PDTC group and in the dexamethasone group decreased compared with the allograft group by immunohistochemistry. On day 15, the mRNA and protein expression of TLR2, MyD88 and NF-κB p65 in the PDTC group and the dexamethasone group were less than in the allograft group (p < 0.05). CONCLUSIONS: Expression of TLR2, MyD88 and NF-κB p65 in rat corneal graft increased significantly and concurred with the allograft rejection, but were effectively inhibited by the treatment with dexamethasone and PDTC after PK. Dexamethasone could improve corneal allograft survival by the TLR2/MyD88/NF-κB axis. PDTC could suppress corneal graft rejection by inhibiting the activity of NF-κB. The TLR2/MyD88/NF-κB axis maybe a potential therapeutic target for corneal allograft rejection.
Subject(s)
Antioxidants/pharmacology , Glucocorticoids/pharmacology , Graft Rejection/prevention & control , Keratoplasty, Penetrating , Myeloid Differentiation Factor 88/genetics , NF-kappa B/genetics , Toll-Like Receptor 2/genetics , Allografts , Animals , Blotting, Western , Cells, Cultured , Dexamethasone/pharmacology , Gene Expression Regulation/physiology , Graft Rejection/genetics , Graft Rejection/metabolism , Immunoenzyme Techniques , Male , Myeloid Differentiation Factor 88/metabolism , NF-kappa B/metabolism , Postoperative Complications , Proline/analogs & derivatives , Proline/pharmacology , RNA, Messenger/genetics , Rats , Rats, Sprague-Dawley , Rats, Wistar , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Thiocarbamates/pharmacology , Toll-Like Receptor 2/metabolismABSTRACT
RelA, the most important regulator of NF-kB activity, and its mechanisms in keratoplasty immune rejection have not been fully investigated. In the present study, lentivirus-mediated silencing of RelA expression in a bone marrow-derived dendritic cell (BMDC) model was tested. The BMDCs were transfected with RelA-shRNA to induce an immature, maturation-resistant and tolerogenic phenotype, while not significantly changing IFN-γ, IL-10 and IL-17 expression. A fully allogeneic rat cornea transplant model was established for in vivo studies. The allograft mean survival time (MST) of lv-shRelA-DC injection groups were significantly longer than the untreated BMDC group and control group. The corneal opacity and neovascularization scale of the lv-shRelA-DC injection groups were slight compared to pair control others. Postoperative flow cytometric analysis revealed that the percentage of Treg positive cells was dramatically increased in animals that received an lv-shRelA-DC injection. ELISA and qRT-PCR analyses of serum showed that IFN-γ and IL-17 expression were suppressed by lv-shRelA-DC treatement. In vivo experiments demonstrated that IL-10 induced immunosuppression was partly attributed to injection of lv-shRelA-DC throughout the experiment, differing from the general anti-inflammatory factors. Luciferase and Chromatin IP evaluation showed that RelA knockdown in BMDCs significantly reduces DNA binding to IFN-γ, IL-10 and the IL-17 promoter and inhibited of transcriptional activity. Taken together, this study illustrates a significant role of RelA in mediating the corneal neovascularization by affecting IL-17 expression. Our comprehensive analysis shows that the significant role of RelA provides a novel and feasible therapeutic approach for the prevention of corneal allograft rejection.