RESUMO
BACKGROUND: Previous studies have observed the expression of formyl peptide receptors (FPRs) in neural stem/progenitor cells (NSPCs) and confirmed that FPRs can promote the migration of NSPCs and induce them to differentiate into neurons. FPRs ligands are present in damaged tissues, but the binding of different ligands with FPRs may lead to different and even opposite biological effects. OBJECTIVE: To investigate the effect on the differentiation of NSPCs into neurons after the binding of the ligands produced following spinal cord injury with FPRs. METHODS: Immunofluorescence staining, western blot and flow cytometry were used to analyze the expression of FPRs in NSPCs. Immunofluorescent staining with confocal microscope detection was used to analyze the effect of homogenates of the spinal cord on the differentiation of FPR1+or FPR2+NSPCs into neurons. RESULTS AND CONCLUSION: Some of NSPCs expressed FPR1 and FPR2, not only on the cell membrane, but also in the cytoplasm. The expression level of FPR1 was obviously lower than that of FPR2. The homogenate group for FPR1+or FPR2+NSPCs could produce more β-III tubulin-positive cells and fewer GFAP-positive astrocytes, and the effects could be blocked by FPR1 or FPR2 inhibitor Boc2 or WRW4. These experimental findings show that the spinal cord homogenate can induce FPR1 or FPR2 positive NSPCs to differentiate into neurons and inhibit their differentiation to astrocytes, and moreover, this effect is specific.
RESUMO
A new all-solid state electrode modified with poly ( o-aminophenol-co-o-phenylenediamine ) film was prepared by cyclic voltammetry.The electrochemical response of the electrode to various solutions in the available acidity range of 1.00 × 10-12-10.0 mol/L was studied by cyclic voltammetry.The results showed that the reduction peak potentials and the available acidity of solution showed good linear relationship in 3 stages of 1.00×10-10-0.10 mol/L, 0.10-2.00 mol/L and 2.00-10.0 mol/L respectively, and the regression equations were Epc=0.0456lgC(H+)-0.295, Epc=0.0803c(H+)-0.309, and Epc=0.0278c(H+)-0.188, respectively.There were similar responses in the solutions of H2 SO4 , HNO3 and HClO4 in the concentration range of 1.00-8.00 mol/L.The preparation method of electrode was simple, and the determination range of available acidity was as wide as 1.0 ×10-10-10.0 mol/L, which laid the foundation for the development of solid-state electrochemical sensors for determination of acidity of high acidity solution.