The Split-Cre system consists of two inactive polypeptides: NCre and CCre, which can be recombined into an active full-length Cre under certain conditions. This system is typically used with LoxP. To develop an efficient Split-Cre system, this study used Rma intein from Rhodothermus marinus to split Cre and screened out the split site S102 which could efficiently mediate the recombination of Cre in the "Traffic Light" reporter cell line. Moreover, the S102 Split-Cre system was delivered to mice by dual-adeno-associated virus (AAV), and it was demonstrated that the efficiency of the Rma intein-mediated S102 Split-Cre system was comparable to the full-length Cre in mice. This system lays a foundation for both basic and applied research on Split-Cre.
Inteins/genetics* ; Animals ; Integrases/biosynthesis* ; Mice ; Dependovirus/metabolism* ; Bacterial Proteins/genetics* ; Recombination, Genetic ; Humans

Objective To investigate the effect of proanthocyanidins(PC)on the neurite outgrowth of rat dorsal root ganglion(DRG)neurons.Methods In vitro,primary rat DRG neurons were cultured wtih a series of concenteation of PC to assess the effect of PC on the number and length of neurites as well as the morphology of growth cone.In vivo,the expression of growth associated protein 43(GAP43)in the early stage of injury was detected using the sciatic nerve crush model.Finally,the impact of PC on nerve growth factor(NGF)expression in DRG neurons was evaluated in vitro using immunofluorescence and ELISA.Results PC significantly increased the number and length of neurites and the number of pseudopodium in growth cones of DRG neurons.PC also promoted the expres-sion of GAP43 in the early stage of sciatic nerve injury in rats and enhanced the expression of NGF in DRG neurons.Conclusion PC may promote the neurite outgrowth by increasing the expression of NGF in DRG neurons.

After peripheral nerve injury (PNI),myelinated Schwann cells undergo demyelination,dedifferentiation and proliferation,then migrate along basal lamina tubes and align to form the longitudinal cell strands known as bands of Btüngner,which creates suitable conditions for axonal regeneration and remyelination.By reviewing literature,we found that the expression of a transcriptional factor c-Jun increased during demyelination process after PNI,and increasing evidences suggested that demyelination and c-Jun signaling pathways were closely related.This review summarized the research situation and progress of c-Jim signaling pathways regulating demyelination process after peripheral nerve injury.

BACKGROUND:Stromal cellderived factor 1 in chemotactic migration of endogenous neural stem cells plays a very important role, but the specific migration mechanism is unclear
OBJECTIVE:To observe the effects of exogenous stromal cellderived factor 1 on chemotactic migration and proliferation of neural stem cells in the rat hippocampus
METHODS:Exogenous stromal cellderived factor 1 (5μL, 500μ/L) was injected into the hippocampus of Sprague-Dawley rats to establish animal models. Brain tissues were taken after days 3, 7, 14 and 21 of perfusion to prepare paraffin sections. Thereafter, nestin expression in the injection region and hippocampus was detected using immunohistochemical method. Experimental control and blank control groups were set.
RESULTS AND CONCLUSION:Paraffin section immunohistochemical results displayed the number of nestin-positive cells in the injection and the hippocampus was gradual y increased. At 3 and 7 days, nestin expression was a little and increased at 14 days, forming a migration tendency to the injection region. At 21 days, there were more nestin-positive cells in the injection area and hippocampus. However, there were no changes as above in the experimental control and blank control groups. The results showed that exogenous stromal cellderived factor 1 may induce the proliferation of neural stem cells in the hippocampus and may be involved in chemotactic migration of endogenous neural stem cells.

Objective To apply the exogenous monocyte chemoattractant protein-1 (MCP-1) to induce the neural stem cells in vivo.Methods 64 adult male Sprague-Dawley rats were randomly divided into blank (n=4), control (n=30) and experimental (n=30) groups. The experimental group was injected with MCP-1 into the cerebra, and the control group with PBS, and the blank group with no intervention.The number of nestin positive cells in brain was observed with immunohistochemistry 3, 5, 7, 14, 21 days after injection. Results The number of nestin positive cells increased with time in the cortex and hippocampus in the experimental group (P<0.001). There was no significant difference between the control group and the blank group (P>0.05). Conclusion Exogenous MCP-1 may induce the increase of neural stem cells in vivo.

Objective To explore the relationship among expression of peroxisome proliferators-activated receptors γ (PPARγ) in human glioma, malignancy and outcome. Methods The level of PPARγ was detected with immunohistochemistry in the glioma from 48 cases with glioma. The progression-free survival and overall survival were compared with Kaplan-Meier survival curve between the patients with more expression of PPARγ and less ones. Results The expression of PPARγ decreased (P<0.01) with the the tumor malignancy increasing from grade I to IV, which was negatively correlated (r=-0.770, P<0.01). Both the progression-free and overall survival time were significant difference between the patients with more expression of PPARγ and less ones (P<0.01). Conclusion PPARγ expression correlates with the malignancy of human glioma, which may predict the outcome of the patients.

OBJECTIVETo observe the inhibition of flavonoids extract (FE) from Inula britannica on oxidative stress in rat aorta after balloon injury.

METHODThe model of vascular intimal hyperplasia was established by balloon injury. The rats were randomly divided into four groups: control, model, FE and captopril (CAP, positive control). The FE group was treated by intragastric administration with FE in dose of 12.5, 25, 50 mg x kg(-1) x d(-1). The level of malondialdehyde (MDA) and superoxide dismutase (SOD) in serum were detected by thiobarbituric acid (TAB) method and xanthine oxidase method respectively, and superoxide anion (O2-) in vessel was detected by dihydroethidium (DHE) staining. The histochemistry, immunohistochemistry and Western blot were used to observe the changes of appearance and SOD expression in vascular tissues after balloon injury.

RESULTThe best concentration of FE to rats was 50 mg x kg(-1) x d(-1). The neointima thickness in the model group was significantly higher than that in the FE group (50 mg x kg(-1) x d(-1)) and control group at 14 days after balloon injury (P < 0.01). The lever of MDA in serum of FE group was decreased (P < 0.01) and SOD was increased (P < 0.05) in both serum and vascular tissues. The level of O2*- in the drug group was lower than that in the model group.

CONCLUSIONFE can enhance the antioxidation capacities of vessel tissues by suppressing the formation of O2- induced by injury, by which FE inhibites neointima formation after balloon injury in rat.

Animals ; Antioxidants ; administration & dosage ; chemistry ; Aorta ; drug effects ; metabolism ; Blood Vessels ; drug effects ; metabolism ; Catheterization ; adverse effects ; Down-Regulation ; Ethidium ; analogs & derivatives ; blood ; metabolism ; Flavonoids ; administration & dosage ; chemistry ; Inula ; chemistry ; Male ; Oxidative Stress ; drug effects ; Random Allocation ; Rats ; Superoxide Dismutase ; blood ; metabolism

Angiotensin Ⅱ(AngⅡ)can induce the expression of its precursor,angiotensinogen,in vascular smooth muscle cells(VSMC),which is related with increased activating protein-1(AP-1)binding to its cis-element located in the angiotensinogen gene promoter.In the present study,cycloheximide(CHX)was used as an inhibitor to interrupt c-Jun,the role of AP-1 in AngⅡ-induced its precursor gene activation was investigated by DNA-protein interaction and immunoblotting.The results showed that the level of c-Jun,the component of transcription factor AP-1,was significantly increased in the nucleus of VSMC after AngⅡ treatment.The majority of c-Jun was found in the nucleus but hardly detected in the cytoplasm by immunocytochemistry staining.Immunoprecipitation assays confirmed that AngⅡ could induce serine phosphorylation of c-Jun.EMSA results indicated that the level of phosphorylated of c-Jun had a positive correlation with AP-1 binding activity to cis-acting element of angiotensinogen gene and transcription activation of angiotensinogen.CHX inhibited AngⅡ-induced binding activity of AP-1 by reducing the phosphorylation of c-Jun,though it did not affect the expression of c-Jun.These findings suggest that the AP-1 phosphorylation induced by AngⅡ is one of the important mechanisms whereby AngⅡ regulates its precursor gene expression in feedback manner.It is found that CHX is an inhibitor to phosphorylation of c-Jun.

Objective To investigate the relationship between NF-?B activation and the expression of metastasis correlation factors.Methods The expression of NF-?B,COX-2,ICAM-1,VCAM-1 and MMP9 in colorectal cancer and normal tissues was detected using Western blotting.Results(1)The expression level of NF-?B was higher in cancer tissues than that in normal tissues(P

Teachers are principal parts in the innovation and implementation of teaching.Along with the deepening transformation of new medical teaching mode,higher demands have been set for the construction of teachership and for the education and training of teachers.The article gives an analysis on several issues that should be given attention to in the teacher training.