Objective To explore the effect of chemokine SDF-1 on the proliferation,migration and in vitro of human endothelial progenitor cells(EPCs).Methods The expression of CXCR4 and SDF-1 on EPCs was detected with immunocytochemistry.Proliferation,migration and in vitro tubulogenesis of EPCs was detected by MTT,Millicell chemotaxis and three-diamensional in vitro Matrigel assays,respectively.Results SDF-1 and CXCR4 were expressed on EPCs.SDF-1 induced proliferation,migration and tubulogenesis of EPCs.However,AMD3100 abolished the effects induced by SDF-1.Conclusion The SDF-1/CXCR4 axis possibly plays a critical role in regulating vasculogenesis of EPCs.

OBJECTIVETo generate a mouse model of chronic hepatitis B (CHB) infection by performing in vivo transduction of hepatitis B virus (HBV) covalently closed circular (ccc)DNA.

METHODSNude mice were injected with HBV cccDNA at doses of 1.5, 1.0 or 0.5 mug/ml. A control group was generated by giving equal injection volumes of physiological saline. The serum levels of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) on post-injection days 1 and 3, weeks 1-6, 8 and 10 were assayed by reflection immunoassay. At post-injection week 10, all animals were sacrificed and liver tissues were collected. Copies of HBV DNA in serum and liver tissue were detected by real-time PCR. HBV antigens in liver tissue were detected of by immunohistochemistry. Pathological analysis of liver tissue carried out with hematoxylin-eosin staining. Linear correlation of data was determined by statistical analysis.

RESULTSHBsAg and HBeAg were detected in sera from all three groups of cccDNA-injected mice staring at post-injection day 1 and lasting through week 10. The levels of HBsAg over the 10-week period showed two patterns of increase-decrease;the lowest level was detected at week 4 and the highest level was detected at week 8. In contrast, the levels of HBeAg over the 10-week period showed three patterns of increase-decrease; the lower levels were detected at weeks 2 and 4 and the higher levels at weeks 3 and 6. HBV DNA copies in liver tissues showed a cccDNA dose-dependent descending trend over the 10-week study period (1.5 mug/ml:1.14E+07 ± 6.51E+06 copies/g, 1.0 mug/ml:9.81E+06 ± 9.32E+06 copies/g, and 0.5 mug/ml:3.72E+06 ± 2.35E+06 copies/g; Pearson's r =0.979). HBV DNA copies in sera showed the pattern of 1.0 mug/ml cccDNA more than 1.5 mug/ml cccDNA more than 0.5 mug/ml cccDNA, and in general were higher than those detected in the liver tissues. Liver tissues from all cccDNA-injected mice showed positive immunohistochemistry staining for both HBsAg and HBeAg. HE staining showed that the liver tissues of all cccDNA-injected mice had severe fatty and vacuolar degeneration and less obvious structure of liver lobules (compared to the liver tissues from control mice).

CONCLUSIONThe CHB mouse model successfully established in this study by in vivo transduction of HBV cccDNA may represent a useful tool to study the pathogenic mechanisms and potential antiviral treatments of human CHB.

Animals ; DNA, Circular ; administration & dosage ; DNA, Viral ; administration & dosage ; Disease Models, Animal ; Hepatitis B Surface Antigens ; blood ; Hepatitis B e Antigens ; blood ; Hepatitis B virus ; genetics ; physiology ; Hepatitis B, Chronic ; virology ; Male ; Mice ; Mice, Nude ; Transduction, Genetic ; Virus Replication

OBJECTIVE: To investigate the effects of blocking the activation of ERK pathway on the expression of matrix metalloproteinase-9 (MMP-9) and the formation of cerebral edema in SD rats after brain injury. METHODS: Ninety SD rats were randomly divided into 3 equal groups, including a sham-operated group, modified Feeney's traumatic brain injury model group, and ERK inhibition group where the ERK inhibitor SCH772984 (500 μg/kg) was injected via the femoral vein 15 min before brain trauma. At 2 h and 2 days after brain trauma, the permeability of blood-brain barrier was assessed by Evans blue method, the water content of the brain tissue was determined, and the phosphorylation level of ERK and the expression level of MMP-9 mRNA and protein were measured by RT-PCR and Western blotting. RESULTS: Compared with the sham-operated group, the rats with brain trauma exhibited significantly increased level of ERK phosphorylation at 2 h and significantly increased expression of MMP-9 mRNA and protein 2 days after the injury ( < 0.01). Treatment with the ERK inhibitor significantly decreased the phosphorylation level of ERK after the injury ( < 0.01), suppressed over-expression of MMP-9 mRNA and protein 2 days after the injury ( < 0.01). The permeability of blood-brain barrier increased significantly 2 h after brain trauma ( < 0.05) and increased further at 2 days ( < 0.01); the water content of the brain did not change significantly at 2 h ( > 0.05) but increased significantly 2 d after the injury ( < 0.01). Treatment with the ERK inhibitor significantly lowered the permeability of blood-brain barrier and brain water content after brain trauma ( < 0.01). CONCLUSIONS Blocking the activation of ERK pathway significantly reduced the over-expression of MMP-9 and alleviates the damage of blood-brain barrier and traumatic brain edema, suggesting that ERK signaling pathway plays an important role in traumatic brain edema by regulating the expression of MMP-9.
Animals ; Brain Edema ; drug therapy ; etiology ; Brain Injuries, Traumatic ; complications ; drug therapy ; Gene Expression Regulation, Enzymologic ; drug effects ; Indazoles ; pharmacology ; therapeutic use ; MAP Kinase Signaling System ; drug effects ; Matrix Metalloproteinase 9 ; genetics ; Piperazines ; pharmacology ; therapeutic use ; Protein Kinase Inhibitors ; pharmacology ; therapeutic use ; Random Allocation ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To investigate the effects of blocking the activation of ERK pathway on the expression of matrix metalloproteinase-9 (MMP-9) and the formation of cerebral edema in SD rats after brain injury. METHODS: Ninety SD rats were randomly divided into 3 equal groups, including a sham-operated group, modified Feeney's traumatic brain injury model group, and ERK inhibition group where the ERK inhibitor SCH772984 (500 μg/kg) was injected via the femoral vein 15 min before brain trauma. At 2 h and 2 days after brain trauma, the permeability of blood-brain barrier was assessed by Evans blue method, the water content of the brain tissue was determined, and the phosphorylation level of ERK and the expression level of MMP-9 mRNA and protein were measured by RT-PCR and Western blotting. RESULTS: Compared with the sham-operated group, the rats with brain trauma exhibited significantly increased level of ERK phosphorylation at 2 h and significantly increased expression of MMP-9 mRNA and protein 2 days after the injury ( < 0.01). Treatment with the ERK inhibitor significantly decreased the phosphorylation level of ERK after the injury ( < 0.01), suppressed over-expression of MMP-9 mRNA and protein 2 days after the injury ( < 0.01). The permeability of blood-brain barrier increased significantly 2 h after brain trauma ( < 0.05) and increased further at 2 days ( < 0.01); the water content of the brain did not change significantly at 2 h ( > 0.05) but increased significantly 2 d after the injury ( < 0.01). Treatment with the ERK inhibitor significantly lowered the permeability of blood-brain barrier and brain water content after brain trauma ( < 0.01). CONCLUSIONS Blocking the activation of ERK pathway significantly reduced the over-expression of MMP-9 and alleviates the damage of blood-brain barrier and traumatic brain edema, suggesting that ERK signaling pathway plays an important role in traumatic brain edema by regulating the expression of MMP-9.
Animals ; Blood-Brain Barrier ; Brain Edema ; Brain Injuries, Traumatic ; MAP Kinase Signaling System ; Matrix Metalloproteinase 9 ; Rats ; Rats, Sprague-Dawley