This study was purposed to construct prokaryotic expression vector and to investigate the expression of Notch ligand Jagged1 in E.coli. An expression vector pET-hJagged1 was constructed, which can be inserted in Jagged1 with different lengths, but the DSL domain of human Jagged1 should be contained. Then the recombinant plasmids were transformed into the competent cell of E.coli BL21, and the expression of the fusion protein was induced by IPTG. Fusion protein was purified from the supernatant of cell lysates via the Nickel affinity chromatography. The results showed that prokaryotic expression vectors pET-hJagged1 (Bgl II), pET-hJagged1 (Hind I) and pET-hJagged1 (Stu I) were successfully constructed, but only pET-hJagged1 (Stu I) could express the soluble TRX-hJagged1. The purified TRX-Jagged1 protein could be obtained via the Nickel affinity chromatography, and then confirmed by Western Blot. It is concluded that prokaryotic expression vector pET-hJagged1 is successfully constructed, but only pET-hJagged1 (Stu I) can express the soluble TRX-hJagged1 and the TRX-Jagged1 fusion protein is obtained through the prokaryotic expression system, which laid a solid foundation for further to explore the effects of Jagged1 in hematopoietic and lymphoid system.
Calcium-Binding Proteins ; genetics ; metabolism ; Cloning, Molecular ; Escherichia coli ; metabolism ; Genetic Vectors ; Intercellular Signaling Peptides and Proteins ; genetics ; metabolism ; Jagged-1 Protein ; Membrane Proteins ; genetics ; metabolism ; Plasmids ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Serrate-Jagged Proteins

This study was aimed to investigated the mRNA expression levels of Notch ligands- Delta-like-1 and Jagged-1 in bone marrow mesenchymal stem cells of patients with myelodysplastic syndrome (MDS), and to explore their relation with onset of MDS. Bone marrow mesenchymal stem cells of 38 patients with MDS and 16 normal subjects as control were collected to detect mRNA expression of Delta-like-1 and Jagged-1 by using real-time quantitative polymerase chain reaction. The results showed that the expression levels of Delta-like-1 and Jagged-1 in mesenchymal stem cells of MDS patients were significantly higher than that in normal controls (P < 0.05). According to WHO criteria, the mRNA expression of Delta-like-1 in RA/RAS, RCMD and RAEB groups were significantly higher than that in normal controls (P < 0.05), the mRNA expression of Jagged-1 in RAEB group was also significantly higher than that in normal controls (P < 0.05). The mRNA expression of Delta-like-1 was significantly correlated with the proportion of blasts in the bone marrow of MDS patients (r = 0.502, P < 0.05). The expression levels of Delta-like-1 and Jagged-1 in MDS patients with abnormal karyotypes were significantly higher than those in MDS patients with normal karyotypes (P < 0.05). The mRNA expression of Delta-like-1 in higher risk group according to International Prognostic Scoring System was significantly higher than that in lower risk group (P < 0.05), there was no significant difference in Jagged-1 expression levels between higher risk group and lower risk group (P > 0.05). It is concluded that the changes of Delta-like-1 and Jagged-1 expression level in MSC may play a role in the pathogenesis of myelodysplastic syndrome.
Calcium-Binding Proteins ; genetics ; Gene Expression Regulation, Neoplastic ; Humans ; Intercellular Signaling Peptides and Proteins ; genetics ; Intracellular Signaling Peptides and Proteins ; genetics ; Jagged-1 Protein ; Membrane Proteins ; genetics ; Mesenchymal Stromal Cells ; metabolism ; Myelodysplastic Syndromes ; genetics ; RNA, Messenger ; biosynthesis ; Serrate-Jagged Proteins

Jagged-1 protein is one of the ligands belonging to Notch signaling pathway. Notch signaling pathway is one of the major signaling pathways mediated by contact between cells and plays an important role to regulate the process of proliferation and differentiation of hematopoietic cells in the hematopoietic microenvironment. To study the biological effect after the combination of receptor and ligand in Notch signaling pathway and the mechanism of Notch signaling pathway in bone marrow stromal cells mediated-drug resistance, a NIH-3T3 cell line over-expressing Jagged-1 protein was constructed for further research purposes. A full coding region of Jagged-1 gene was cloned and inserted into eukaryotic expression plasmid to construct pEGFP-IRES2-Jagged-1 eukaryotic expression vector, then transfected into NIH-3T3 cell line, a mammalian cells. As a result Western blot analysis confirmed that the transfectant NIH-3T3 cells highly expressed Jagged-1 protein and flow cytometry analysis confirmed that the NIH-3T3-pEGFP-IRES2-Jagged-1 cell line over-expressed Jagged-1 protein was monoclonal after screened by selective medium and limiting dilution analysis. It is concluded that the pEGFP-IRES2-Jagged-1 eukaryotic expression vector and a stable transfectant monoclonal NIH-3T3 cell line are successfully established. The construction of the stable transfectant monoclonal NIH-3T3 cell line which overexpressed Jagged-1 protein, provides the conditions to further study the mechanism of the bone marrow stromal cell-mediated drug resistance and to discover the new drug targets.
Animals ; Calcium-Binding Proteins ; genetics ; Genetic Vectors ; Humans ; Intercellular Signaling Peptides and Proteins ; genetics ; Jagged-1 Protein ; Ligands ; Membrane Proteins ; genetics ; Mice ; NIH 3T3 Cells ; Plasmids ; Receptors, Notch ; metabolism ; Serrate-Jagged Proteins ; Signal Transduction ; Transfection

BACKGROUNDNotch activation leads to transcriptional suppression of lineage-specific genes, inhibiting differentiation in response to inductive signals. The Notch signal system contains three parts: Notch molecules, Notch ligands and effectors. Delta4 is a newly-discovered Notch ligand which has received the attention of few detailed studies. This study sought to explore the biological function of Delta4 and observe its effects on 32D cell differentiation.

METHODSDelta4-expressing vector pTracer.CMV.Delta4.FLAG was constructed using molecular biological techniques. CHO cells stably transfected with pTracer.CMV.Delta4.FLAG were confirmed to have a Delta4 protein band via Western blotting. High-expression Delta4-CHO clones were selected for the following functional studies. Notch1-CHO and Notch2-CHO were used as host cells. After transiently transfecting with transition protein 1 (TP1), Delta4 activity was compared in both cell lines by means of luciferase analysis. CHO cells were incubated with Notch1-32D cells that had been transfected with Notch1 and were observed for granulocyte colony-stimulating factor (G-CSF)-induced differentiation. Jagged2-CHO and Delta4-CHO cells transfected with the Notch ligands Jagged2 and Delta4, respectively, were incubated with Notch1-32D cells to observed inhibition of Notch on G-CSF-induced differentiation.

RESULTSThe vector pTracer.CMV.Delta4.FLAG was constructed successfully. CHO cells were stably transfected with the vector pTracer.CMV.Delta4.FLAG. Two CHO cell lines expressing Delta4 at high levels were selected for use in the study. Delta4 was found to induce signal activity via both Notch1 and Notch2 and the induction of signaling activity was stronger in Notch2 cells than in Notch1 cells. Compared with other Notch ligands, Delta4 was slightly weaker than Jagged2, but stronger than Delta1 and Jagged1 in terms of Notch1 ligands. In terms of Notch2, Delta4 had a strong signaling activity, but was weaker than Delta1, Jagged1, and Jagged2. Jagged2 could inhibit Notch1-32D cell differentiation induced by G-CSF, but Delta4 could not.

CONCLUSIONSDelta4 induces both Notch1 and Notch2 activity and is a ligand for both of them. The effect of Delta4 is stronger on Notch2 than that on Notch1. Jagged2 can inhibit Notch1-32D cell differentiation induced by G-CSF, but Delta4 cannot.

Animals ; CHO Cells ; Calcium-Binding Proteins ; Cell Differentiation ; Cricetinae ; Intercellular Signaling Peptides and Proteins ; Intracellular Signaling Peptides and Proteins ; Jagged-1 Protein ; Jagged-2 Protein ; Membrane Proteins ; genetics ; physiology ; Mice ; Receptor, Notch1 ; Receptor, Notch2 ; Receptors, Cell Surface ; physiology ; Serrate-Jagged Proteins ; Signal Transduction ; Transcription Factors ; physiology

OBJECTIVETo investigate the effects of triptolide on Notch receptor and ligand expressions in rats with adjuvant-induced arthritis (AA).

METHODSForty rats were randomly divided into normal control (NC) group, model (MC) group, methotrexate group and triptolide groups. Rat models of AA were established by an intradermal injection of 0.1 mL Freund's complete adjuvant into the right paw. Twelve days after the injection, the rats were treated with corresponding drugs for 30 days; the rats in NC group and MC group were given saline only. Paw edema volume (E), arthritis index (AI), pulmonary function, histomorphologies, and Notch receptor/ ligand expression in the lung tissue were analyzed after the treatments.

RESULTSCompared with the NC group, E, AI, Notch3, Notch4, and Delta1 expressions in the lung tissues significantly increased while pulmonary function and pulmonary expressions of Notch1, Jagged1, and Jagged2 significantly decreased the model rats (P<0.01). Compared with the MC group, triptolide-treated rats showed significantly improved pulmonary functions, increased expressions of Notch1, Jagged1, and Jagged2 and decreased expressions of Notch3, Notch4, and Delta1 in the lungs (P<0.05, P<0.01); the therapeutic effect of triptolide was better than that of methotrexate.

CONCLUSIONTriptolide can reduce inflammatory reaction and immune complex deposition to improve joint and pulmonary symptoms in rats with AA possibly by up-regulating the expressions of Notch3, Notch4, and Delta1 and down-regulating the expressions of Jagged1, Jagged2, and Notch1.

Animals ; Arthritis, Experimental ; drug therapy ; metabolism ; Calcium-Binding Proteins ; metabolism ; Diterpenes ; pharmacology ; Down-Regulation ; Drugs, Chinese Herbal ; Epoxy Compounds ; pharmacology ; Intercellular Signaling Peptides and Proteins ; metabolism ; Intracellular Signaling Peptides and Proteins ; metabolism ; Jagged-1 Protein ; Jagged-2 Protein ; Ligands ; Lung ; drug effects ; metabolism ; physiopathology ; Membrane Proteins ; metabolism ; Methotrexate ; pharmacology ; Phenanthrenes ; pharmacology ; Rats ; Receptor, Notch3 ; Receptor, Notch4 ; Receptors, Notch ; metabolism ; Respiratory Insufficiency ; drug therapy ; Serrate-Jagged Proteins

OBJECTIVETo investigate the biological behavior including survival and proliferation of CD34 + CD38--Lin--cells when they are cultured at single cell level.

METHODSPurified umbilical cord blood CD34 + CD38--Lin--cells were separated at single cell level in 96-well plates using flow cytometry for four groups: control group (CD34 + CD38--Lin--cell plus stem cell medium) , Shh group (CD34 + CD38--Lin--cell plus stem cell medium and Shh), BMP-4 group (CD34 + CD38--Lin--cell plus stem cell medium and BMP-4), Jagged-1 group (CD34 + CD38--Lin--cell plus stem cell medium and Jagged-1). Methylcellulose medium was used in the colony-forming experiment which was also in four groups as previously. The number of cells and colony-forming units in each well for the four groups was evaluated at different time points (day 1, 3, 7) with fluorescence microscopy counting method.

RESULTSDivision of single cell was observed to be amplified in all of these groups from day 3. And meanwhile, after 1-week culture, the survival rates for the treated groups were all higher than the control group (Jagged-1 group > BMP-4 group > Shh group > control), while the cell number in each well was also highest in the Jagged-1 group (Jagged-1 group > BMP-4 group > control). The number of wells with a cell number of zero was significantly fewer in all treated groups (especially the Jagged-1 group) than in the control group; meanwhile, the number of wells with a cell number higher than 17 was evidently higher in all the treated groups (especially the BMP-4 group) more than controls. Colony-forming units for erythroid (BFU-E), granulocyte (CFU-G), macrophage (CFU-M), and granulocyte macrophage (CFU-GM) were observed for all of these experimental groups, and there was no significant difference between the four experimental groups.

CONCLUSIONSCD34 + CD38 - Lin - cell can achieve the survival, self-renewal and proliferation when cultured at single cell level, and the adding of Shh, BMP-4, and Jagged-1 can enhance such capabilities. However, CD34 + CD38 - Lin - cell can only maintain cell totipotency in its niche.

ADP-ribosyl Cyclase 1 ; metabolism ; Antigens, CD34 ; metabolism ; Bone Morphogenetic Protein 4 ; chemistry ; Calcium-Binding Proteins ; chemistry ; Cell Culture Techniques ; Cell Proliferation ; Cell Survival ; Cells, Cultured ; Colony-Forming Units Assay ; Culture Media ; Fetal Blood ; cytology ; Hedgehog Proteins ; chemistry ; Hematopoietic Stem Cells ; cytology ; Humans ; Intercellular Signaling Peptides and Proteins ; chemistry ; Jagged-1 Protein ; Membrane Proteins ; chemistry ; Serrate-Jagged Proteins

The Notch signaling pathway has been implicated in the regulation of cell-fate decisions such as differentiation of embryo stem cells and neural stem cells into neurons. We cultured human mesenchymal stem cells (hMSCs) in vitro and induced hMSCs to differentiate into neural cells by beta-mercaptoethanol (beta-ME), DMSO and 3-tert-butyl-4-hydroxyanisole (BHA). Immunocytochemistry was utilized to detect neuron-specific enolase (NSE) and Nissl body, and flow cytometry was used to determine cell growth phases. The expressions of signal molecules involved in the Notch pathway such as Notch1, Jagged 1 (JAG1), presenilin 1 (PS1) and hairy and enhancer of split 1(HES1) were observed by RT-PCR and immunofluorescent techniques. The results were as follows: (1) Before induction, the percentage of hMSCs at G(0)/G(1) was 58.5%, and the percentage at S+G(2)/M was 41.5%. After induction, the percentage of hMSCs at G(0)/G(1) increased to 73.1%, 76.2% and 78.1%, respectively on days 2, 4 and 6, and the percentage at S+G(2)/M decreased to 26.8%, 24.8% and 21.9%, respectively; The percentage of NSE-positive cells reached (77+/-0.35) %; Nisslos staining was positive in cytoplasm. (2) Notch1 and JAG1 were both expressed in hMSCs before and after induction, but the mRNA expressions of both Notch1 and JAG1, detected by RT-PCR, decreased obviously after induction(P<0.05). Notch1 mRNA/beta-actin was 1.157, 0.815, 0.756 and 0.570, and JAG1 mRNA/beta-actin was 0.437, 0.350, 0.314 and 0.362, respectively, on days 0, 2, 4 and 6 after induction. The Notch pathway activation participant PS1 mRNA and Notch pathway target gene HES1 mRNA also decreased apparently after induction (P<0.05), and their mRNA/beta-actin was 0.990, 0.449, 0.441, 0.454 and 0.370, 0.256, 0.266, 0.240 on days 0, 2, 4 and 6, respectively. These observations indicate that the expressions of Notch signal molecules were suppressed when hMSCs were induced to differentiate into neural cells. Based on these findings, we propose that low level of Notch signaling activation may contribute to neural cell differentiation.
Basic Helix-Loop-Helix Transcription Factors ; genetics ; Calcium-Binding Proteins ; genetics ; Cell Cycle ; Cell Differentiation ; Flow Cytometry ; Homeodomain Proteins ; genetics ; Humans ; Intercellular Signaling Peptides and Proteins ; genetics ; Jagged-1 Protein ; Membrane Proteins ; genetics ; Mesenchymal Stromal Cells ; cytology ; Neurons ; cytology ; Receptor, Notch1 ; genetics ; Receptors, Notch ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Serrate-Jagged Proteins ; Signal Transduction ; Transcription Factor HES-1

In order to construct a pichia pastoris expression vector containing the extracellular domain of human Jagged1 and the Fc fragment of human IgG1 fusion gene, or containing only the Fc fragment of human IgG1 and to express them in pichia pastoris. The extracellular domain of human Jagged1 gene was cloned from normal human bone marrow cells. After DNA sequencing, the extracellular domain of Jagged1 gene was inserted into pIC-Fc vector constructed previously, which is Pichia pastoris expression vector containing only the Fc fragment of human IgG1. The constructed plasmid was transformed into yeast GS115 by means of electroporation. The recombinant transformants with a high copy number of the plasmid were selected on MD plate with G418. The expression of protein was induced by addition of methanol. Then, protein expression was analyzed by SDS-PAGE. The results indicated that the extracellular domain of human Jagged1 gene was effectively amplified. The DNA sequencing result showed that the constructed plasmid containing hJagged1(ext)-Fc fusion gene was the same as designed. The fusion protein was successfully expressed in Pichia pastoris. It is concluded that the hJagged1(ext) gene has been successfully cloned and expressed, which provides a new fusion protein for further experiments, the hJagged1(ext)-Fc fusion protein can be used as a new stimulator for proliferation of hematopoietic stem/progenitor cells in vitro.
Calcium-Binding Proteins ; biosynthesis ; genetics ; Genetic Vectors ; genetics ; Humans ; Immunoglobulin Fc Fragments ; biosynthesis ; genetics ; Immunoglobulin G ; biosynthesis ; genetics ; Intercellular Signaling Peptides and Proteins ; biosynthesis ; genetics ; Jagged-1 Protein ; Membrane Proteins ; biosynthesis ; genetics ; Pichia ; genetics ; metabolism ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Serrate-Jagged Proteins ; Transfection

OBJECTIVETo study the inhibitory effect of (-)-epigallocatechin-3-gallate (EGCG) on cancer cells line HCT-8 and HT29 and its influence on the expression of HES1 and JAG1.

METHODSColorectal cancer cells line HCT-8 and HT29 were cultured in vitro and treated with different concentrations of EGCG(10 mg/L, 20 mg/L, 35 mg/L). The inhibition of proliferation was tested by MTT analysis. Influence of EGCG on the cell apoptosis and cell cycle of HCT-8 and HT29 were detected with flow cytometry, and gene expression of HCT-8 and HT29 after EGCG treatment with real-time polymerase chain reaction.

RESULTSEGCG affected the proliferation and apoptosis of HCT-8 and HT29. The inhibition rates of the three different concentrations of EGCG were(28.894±5.076)%, (34.903±1.794)%, and (39.028±0.105)% on HCT-8, and (14.682±4.244)%, (22.429±3.847)%, and (29.840±5.076)% on HT29. EGCG caused G(2)/M phase arrest and M phase transition in HCT-8 cell line, and S phase arrest and G2 phase transition in HT29 cell line. EGCG down-regulated HES1 gene expression in both cell lines, however, the differences were not statistically significant(both P>0.05). EGCG upregulated JAG1 gene expression in both cell lines, however only the difference in HCT-8 was statistically significant(0.201±0.018 vs. 0.440±0.077, P=0.029).

CONCLUSIONSEGCG can significantly inhibit the proliferation of HT29 cells and HCT-8 cells by changing cell cycle and inducing cell apoptosis. The mechanism may be related to the upregulation of JAG1 gene expression.

Apoptosis ; drug effects ; Basic Helix-Loop-Helix Transcription Factors ; metabolism ; Calcium-Binding Proteins ; metabolism ; Catechin ; analogs & derivatives ; pharmacology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Colorectal Neoplasms ; pathology ; Flow Cytometry ; HT29 Cells ; Homeodomain Proteins ; metabolism ; Humans ; Intercellular Signaling Peptides and Proteins ; metabolism ; Jagged-1 Protein ; Membrane Proteins ; metabolism ; Serrate-Jagged Proteins ; Transcription Factor HES-1

OBJECTIVE: To observe the changes of pulmonary function and Notch signaling pathway of lung tissues in adjuvant-induced arthritis rats, and to investigate the mechanism of reduced lung function. METHODS: A total of 30 rats were randomly divided into a normal group and a model group. Rats in the model group were induced to establish the adjuvant arthritis AA model by intradermally injecting 0.1 mL Freund's complete adjuvant into the right paw. After 30 days, we observed the paw edema volume, arthritis index, pulmonary function, histomorphology, and Notch receptor/ligand of the lung tissue. RESULTS: Compared with the normal group, the paw edema volume, arthritis index, average expiratory flow within 0.3 s (FEV0.3/FVC), and the level of Notch3, Notch4 and Jagged2 of the lung tissue in the model group was significantly increased, while maximum expiratory flow at 50% of vital capacity (FEF50), maximum expiratory flow at 75% of vital capacity (FEF75), forced expiratory flow (PEF) and the expression of Notch1 of Jagged1 and Delta1 in the lung were significantly decreased (P<0.05, P<0.01). There were significant positive correlations between FEV0.3/FVC and Notch4. FEV0.3/FVC, FEF25, FEF50 and Notch3, Delta1 were negatively correlated, respectively (P<0.05, P<0.01). CONCLUSION While arthritis occurs in AA rats, pulmonary function declines and significantly correlates with the expression of Notch receptor/ligand. The deposition of immune complex in the lung after the injection of CFA activates the Notch signaling pathway, and results in further decline of pulmonary function by signaling cascades.
Animals ; Arthritis, Experimental ; metabolism ; physiopathology ; Calcium-Binding Proteins ; metabolism ; Freund's Adjuvant ; Intercellular Signaling Peptides and Proteins ; metabolism ; Intracellular Signaling Peptides and Proteins ; metabolism ; Jagged-1 Protein ; Lung ; metabolism ; pathology ; Membrane Proteins ; metabolism ; Rats ; Receptors, Notch ; metabolism ; Respiratory Insufficiency ; metabolism ; physiopathology ; Serrate-Jagged Proteins ; Signal Transduction ; Vital Capacity