OBJECTIVETo observe the effect of acupuncture on the Notch signaling pathway in rats with traumatic brain injury and to explore the pathogenesis of acupuncture intervention on traumatic brain injury.

METHODSFeeney's freefall epidural impact method was used to establish a traumatic brain injury model in rats; the rats were randomly divided into a normal group, sham operation group, model group and acupuncture group. Acupuncture was performed in the Baihui (DU 20), Shuigou (DU 26), Fengfu (DU 16), Yamen (DU 15) and Hegu (LI 4) acupoints in the rat, and Yamen was punctured via Fengfu. Then, the rats in each group were randomly divided into three subgroups, namely the day 3 subgroup, day 7 subgroup and day 14 subgroup according to treatment duration. The modified neurological severity scores (mNss) method was used to perform neurobehavioral scoring for evaluating the degree of injury in the rats. The hematoxylin-eosin (HE) staining method was used to observe the pathological change in the brain tissue of rats in each group. Real-time fluorescent quantitative polymerase chain reaction (Q-PCR) technology was used to detect changes in the Notch1, Hes1 and Hes5 gene expression levels in the cortex on the injured side. Western blot was used to detect the protein expression changes.

RESULTSOne day after modeling, the mNss scores in the model group and in the acupuncture group were significantly higher than those in the normal and sham operation groups (P<0.01) ; there was no statistically significant difference between the normal group and the sham operation group. The scores decreased with increased treatment time, and the scores in the acupuncture group decreased more significantly than those in the model group (P<0.01). The pathological examination by the HE staining method demonstrated that the brain tissue of the rats in the acupuncture and model groups relatively significantly changed. The Notch1 gene expression level in the acupuncture group was significantly higher than the level in all of the other groups (P<0.01) ; the Hes1 and Hes5 gene expression levels were also higher in the acupuncture group. The expression changes of the Notch1 and Hes1 protein were consistent with that of mRNA. In each experimental group, the mNss score and the pathological results by the HE staining method were consistent with the mRNA results.

CONCLUSIONAcupuncture could significantly promote high expression levels of Notch1, Hes1 and Hes5 in the brain tissue of traumatic brain injury rats. Therefore, acupuncture might be an important intervention for inducing endogenous stem cell proliferation and for promoting nerve repair.

Acupuncture Points ; Acupuncture Therapy ; Animals ; Brain Injuries ; genetics ; pathology ; therapy ; Brain Ischemia ; pathology ; therapy ; Male ; Nerve Regeneration ; genetics ; Rats ; Rats, Sprague-Dawley ; Receptors, Notch ; genetics ; metabolism ; Reperfusion Injury ; genetics ; therapy ; Signal Transduction ; genetics

The relationship between Kruppel-like factor 4 (KLF4) and the Notch pathway was determined to investigate the effect of KLF4 on the activation of hepatic stellate cells and underlying mechanisms. Fifty SPF BALB/c mice were randomly divided into two groups. A liver fibrosis model was established in 25 mice as the experimental group, and the remaining 25 mice served as controls. On the day 0, 7, 14, and 35, liver tissues were removed for immunofluorescent detection. The Notch pathway inhibitor DAPT was added to the primary original hepatic stellate cells, and KLF4 and Notch-associated factor expression was detected by qRT-PCR. Additionally, the hepatic stellate cell line LX-2 was used to establish control and experimental groups, and was cultured in vitro. LX-2 cells in the experimental groups were treated with DAPT and the Notch activator transforming growth factor-beta 1 separately, whereas those in the control group were given isotonic culture medium. After 48 h, KLF4 expression was examined by Western blotting. After transient transfection of LX-2 cells to increase KLF4, the expression of Notch factor was examined. Immunofluorescence analysis showed that, with the aggravation of liver fibrosis, the absorbance (A) values of KLF4 were decreased (day 0: 980.73±153.19; day 7: 1087.99±230.23; day 14: 390.95±93.56; day 35: 245.99±87.34). The expression of Notch pathway- related factors (Notch-1, Notch-2, and Jagged-1) in the hepatic stellate cell membrane was negatively correlated to KLF4 expression. With the increase of KLF4 expression, Notch-2 (0.73±0.13) and Jagged-1 (0.43±0.12) expression decreased, whereas Notch-1 level was not detectable. When the Notch pathway was inhibited, KLF4 levels generally increased (18.12±1.31). Our results indicate that KLF4 expression is negatively correlated to the Notch pathway in hepatic stellate cells, which may provide a reference for the treatment of hepatic fibrosis.
Animals ; Cell Line ; Cells, Cultured ; Hepatic Stellate Cells ; metabolism ; Kruppel-Like Transcription Factors ; genetics ; metabolism ; Liver Cirrhosis ; metabolism ; Mice ; Mice, Inbred BALB C ; Receptors, Notch ; metabolism ; Signal Transduction ; Transforming Growth Factor beta1 ; metabolism

Notch signaling is highly conserved in evolution and regarded as a key factor in cell fate determination. It mediates cell-to-cell interactions that are critical for embryonic development and tissue renewal, and is involved in the occurrence and metastasis of neoplasm. Recent researches have found that such signaling plays an important role in modulating the differentiation of chondrocytes, osteoblasts and osteoclasts. Dysfunction of Notch signaling can result in many skeletal diseases such as bone tumor, disorders of bone development or bone metabolism.
Animals ; Bone Development ; Bone Diseases ; genetics ; metabolism ; Bone and Bones ; metabolism ; Humans ; Osteoblasts ; cytology ; metabolism ; Osteogenesis ; Receptors, Notch ; genetics ; metabolism ; Signal Transduction

OBJECTIVETo re-analyze the data published in order to explore plausible biological pathways that can be used to explain the anti-aging effect of curcumin.

METHODSMicroarray data generated from other study aiming to investigate effect of curcumin on extending lifespan of Drosophila melanogaster were further used for pathway prediction analysis. The differentially expressed genes were identified by using GeneSpring GX with a criterion of 3.0-fold change. Two Cytoscape plugins including BisoGenet and molecular complex detection (MCODE) were used to establish the protein-protein interaction (PPI) network based upon differential genes in order to detect highly connected regions. The function annotation clustering tool of Database for Annotation, Visualization and Integrated Discovery (DAVID) was used for pathway analysis.

RESULTSA total of 87 genes expressed differentially in D. melanogaster melanogaster treated with curcumin were identified, among which 50 were up-regulated significantly and 37 were remarkably down-regulated in D. melanogaster melanogaster treated with curcumin. Based upon these differential genes, PPI network was constructed with 1,082 nodes and 2,412 edges. Five highly connected regions in PPI networks were detected by MCODE algorithm, suggesting anti-aging effect of curcumin may be underlined through five different pathways including Notch signaling pathway, basal transcription factors, cell cycle regulation, ribosome, Wnt signaling pathway, and p53 pathway.

CONCLUSIONGenes and their associated pathways in D. melanogaster melanogaster treated with anti-aging agent curcumin were identified using PPI network and MCODE algorithm, suggesting that curcumin may be developed as an alternative therapeutic medicine for treating aging-associated diseases.

Aging ; drug effects ; genetics ; Animals ; Cell Cycle ; drug effects ; genetics ; Curcumin ; pharmacology ; Drosophila Proteins ; genetics ; metabolism ; Drosophila melanogaster ; drug effects ; genetics ; Gene Expression Regulation ; drug effects ; Gene Regulatory Networks ; drug effects ; Genes, Insect ; Protein Biosynthesis ; drug effects ; genetics ; Protein Interaction Maps ; drug effects ; genetics ; Receptors, Notch ; genetics ; metabolism ; Ribosomes ; drug effects ; metabolism ; Signal Transduction ; drug effects ; genetics ; Tumor Suppressor Protein p53 ; metabolism ; Wnt Signaling Pathway ; drug effects ; genetics

This study was purposed to investigate the effect of Notch signaling pathway on VEGF promoting the proliferation of rat mesenchymal stem cells (MSC). Rat MSC were cultured in vitro, and the cells in logarithmic growth phase were used for experiments. The inhibitor DAPT was used to block Notch signaling pathway, and the effect of the pathway on VEGF promoting proliferation of MSC was observed. The experiment was divided into 4 groups: control, VEGF, DAPT and VEGF+DAPT. The CCK-8 was used to assay the cells proliferation of each group, while RT-PCR was used to detect the changes of related genes (Notch1, Notch2, Flk-1, Hes-1) at mRNA levels. The results indicated that the cells survival rate MSC in DAPT group and VEGF+DAPT group was low in each time point (24 h, 48 h, 72 h), the cell number decreased, and the cells became rounded. The survival rate of MSC in VEGF group was the highest; the difference of cell survival rate was statistically significant between the groups (P < 0.01); Compared with the control group, the mRNA expression level of Notch1, Notch2 and Flk-1 in VEGF group was raised, while the expression level of Notch1 and Notch2 in DAPT group and VEGF+DAPT group come down, with statistically significant differences (P < 0.05); whereas the mRNA expression level of Hes-1 in VEGF group was down-regulated, but that in DAPT group and VEGF+DAPT group was up-regulated, and the difference was statistically significant (P < 0.05). Flk-1 mRNA level in DAPT group and VEGF+DAPT group was slightly lower, but the difference was not statistically significant (P > 0.05). It is concluded that Notch signaling pathway plays an important role in promoting the proliferation of rat MSC, treated with VEGF, however, the DAPT can weaken this effect.
Animals ; Cell Line ; Cell Proliferation ; drug effects ; Mesenchymal Stromal Cells ; cytology ; drug effects ; metabolism ; RNA, Messenger ; genetics ; Rats ; Receptors, Notch ; metabolism ; Signal Transduction ; drug effects ; Vascular Endothelial Growth Factor A ; pharmacology

Animals ; Carcinogenesis ; Cell Cycle Proteins ; genetics ; metabolism ; Cyclin E ; metabolism ; F-Box Proteins ; genetics ; metabolism ; F-Box-WD Repeat-Containing Protein 7 ; Gene Silencing ; Genes, Tumor Suppressor ; Humans ; Mutation ; Myeloid Cell Leukemia Sequence 1 Protein ; metabolism ; Neoplasms ; genetics ; metabolism ; pathology ; Proto-Oncogene Proteins c-myc ; metabolism ; Receptors, Notch ; metabolism ; Signal Transduction ; TOR Serine-Threonine Kinases ; metabolism ; Ubiquitin-Protein Ligases ; genetics ; metabolism

OBJECTIVETo investigate whether Notch signaling is activated in hepatic stellate cells (HSCs), and to determine whether manipulation of the Notch signaling pathway can effect the activation of HSCs.

METHODSThe expression of Notch signaling components in unactivated or TGF-b1-activated HSC-T6 cells was detected by Taqman Probe-based gene expression analysis. Differential expression of Notch3 and Jagged1 was detected by immunofluorescence analysis. Notch3-mediated expression of the myofibroblastic markers, a-SMA and collagen I, was detected in HSC-T6 cells transfected with pcDNA3.1-N3ICD or Notch3 siRNA by Western blotting.

RESULTSNotch signaling components were expressed in both unactivated and activated HSC-T6 cells, but the TGF-b1-treated cells showed significantly higher expression levels of Jagged1 (3.9-fold, F = 2543.482), Notch3 (4.2-fold, F = 287.982), and HES1 (3.2-fold, F = 1719.851). Transfection-mediated over-expression of Notch3 led to significantly increased expression of a-SMA (6.8-fold, t = 13.157) and collagen I (5.5-fold, t = 9.810) (both P less than 0.01). Transient knock-down of Notch3 expression by siRNA decreased expression of the myofibroblastic markers (a-SMA by approximately 90%, t = 19.863 and collagen I by 84%, t = 10.376; both, P less than 0.01). Moreover, knock-down of Notch3 antagonized the TGF-b1-induced expression of a-SMA and collagen I.

CONCLUSIONNotch signaling may participate in liver fibrogenesis by regulating HSC activation. Selective interruption of Notch3 may represent a new anti-fibrotic strategy to treat liver fibrosis.

Animals ; Calcium-Binding Proteins ; genetics ; metabolism ; Cell Line ; Hepatic Stellate Cells ; metabolism ; Intercellular Signaling Peptides and Proteins ; genetics ; metabolism ; Jagged-1 Protein ; Membrane Proteins ; genetics ; metabolism ; RNA, Messenger ; genetics ; RNA, Small Interfering ; Rats ; Receptor, Notch3 ; Receptors, Notch ; genetics ; metabolism ; Serrate-Jagged Proteins ; Signal Transduction

BACKGROUNDHepatocyte growth factor (HGF) treats ischemic disease by promoting arteriogenesis, however, its mechanism of action is not known. The notch signaling pathway plays an important role in neovascularization. The relationship between the proliferation and migration ability of artery endothelial cells and the Dll4-Notch-Hey2 signaling pathway in the process of arteriogenesis was investigated as a mechanism of action of HGF.

METHODSBased on the prophase study cells and supernatant were harvested at the indicated time after human femoral artery endothelial cells (HFAECs) were infected with adenovirus-HGF (Ad-HGF) at 200 pfu/cell. Cells were analyzed for HGF expression and Notch1, Dll4 and Hey2 expression by ELISA and reverse transcription-PCR (RT-PCR). The changes in the proliferation and migration ability of HFAECs were observed by MTT and Transwell migration experiments. Ad-GFP-infected HFAECs were used as control.

RESULTSCompared with the control group the Ad-HGF group's HGF expression was not increased with time, and the induction by HGF of Notch1, Dll4 and Hey2 gene transcription was not enhanced with an increase of HGF. The proliferation ability of Ad-HGF-transduced HFAECs was enhanced and their migration ability was also enhanced in the presence of HGF.

CONCLUSIONSThrough activating the Dll4-Notch-Hey2 signaling pathway, HGF indirectly promotes the proliferation and migration ability of cells, so that offspring artery branches are formed.

Basic Helix-Loop-Helix Transcription Factors ; genetics ; metabolism ; Cell Line ; Enzyme-Linked Immunosorbent Assay ; Hepatocyte Growth Factor ; genetics ; metabolism ; Humans ; Intercellular Signaling Peptides and Proteins ; genetics ; metabolism ; Receptors, Notch ; genetics ; metabolism ; Repressor Proteins ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; genetics ; physiology

Alzheimer's disease (AD) pathogenesis is characterized by senile plaques in the brain and evidence of oxidative damage. Oxidative stress may precede plaque formation in AD; however, the link between oxidative damage and plaque formation remains unknown. Presenilins are transmembrane proteins in which mutations lead to accelerated plaque formation and early-onset familial Alzheimer's disease. Presenilins physically interact with two antioxidant enzymes thiol-specific antioxidant (TSA) and proliferation-associated gene (PAG) of the peroxiredoxin family. The functional consequences of these interactions are unclear. In the current study we expressed a presenilin transgene in Drosophila wing and sensory organ precursors of the fly. This caused phenotypes typical of Notch signaling loss-of-function mutations. We found that while expression of TSA or PAG alone produced no phenotype, co-expression of TSA and PAG with presenilin led to an enhanced Notch loss-of-function phenotype. This phenotype was more severe and more penetrant than that caused by the expression of Psn alone. In order to determine whether these phenotypes were indeed affecting Notch signaling, this experiment was performed in a genetic background carrying an activated Notch (Abruptex) allele. The phenotypes were almost completely rescued by this activated Notch allele. These results link peroxiredoxins with the in vivo function of Presenilin, which ultimately connects two key pathogenetic mechanisms in AD, namely, antioxidant activity and plaque formation, and raises the possibility of a role for peroxiredoxin family members in Alzheimer's pathogenesis.
Amino Acid Sequence ; Animals ; Drosophila ; metabolism ; physiology ; Drosophila Proteins ; metabolism ; Molecular Sequence Data ; Peroxiredoxins ; chemistry ; genetics ; metabolism ; Presenilins ; chemistry ; metabolism ; Receptors, Notch ; metabolism ; Sequence Alignment ; Signal Transduction

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