Objective To establish a method focusing on regulation of CNN3 gene in the rat hippocampus and help to explore the role of CNN3 gene played in the brain physiology and pathology.Methods One cDNA sequence and three shRNAs targeting CNN3 gene were designed and synthesized.The recombinant lentivirus-mediated expressing and three short hairpin RNA ( shRNA) vectors targeting CNN3 gene in the rats were constructed with engineering technology.All recombinant vectors were intravenously injected into rats hippocampi guided by stereotaxic apparatus.Western blot was performed to explore the best shRNA and to study the changes of CNN3 gene in the rat hippocampus after transfection with the silence and over-expressed vectors.Results The lentivirus-mediated vector expressing CNN3-OE and three shRNA vectors targeting CNN3 gene were successfully constructed.Within eight weeks after transfection, the vectors of CNN3-OE and three CNN3-shRNAs changed the expression of CNN3 gene in the rat hippocampus, in particular, all the protein levels of calponin-3 encoded by CNN3 gene were significantly down-regulated along with the time, with the highest inhibitory rate of 73.6%in the CNN3-shRNA2 group.Significant up-regulation of calponin-3 protein level by 93.88%, was found only on the 14th day after transfection.Conclusions Lentivirus-mediated vectors of CNN3-OE and CNN3-shRNAs may regulate in vivo the CNN3 gene level in the local brain region of rats via stereotactic injection.The study lays a foundation for disease prevention and treatment in the future.

Abstract OBJECTIVE To establish an efficient and simple HPLC-MS/MS method for determination of flucloxacillin in newborn plasma, and to investigate the interaction between ambroxol and flucloxacillin in newborns. METHODS The samples were analyzed by API4000 HPLC-MS/MS. Ultimate XB-C18 column(2.1 mm×100 mm, 5 μm) were carried out. The mobile phase was composed of water-0.1% formic acid(A) and acetonitrile-0.1% formic acid(B). The quantitative analysis of the ion transitions were monitored at m/z 452.6→284.2 for flucloxacillin and m/z 821.4→397.3 for rifampicin(internal standard). RESULTS The linear range of flucloxacillin under this analysis method was 0.20-80 ng·mL-1, and the lower limit of quantification was 0.20 ng·mL-1; The intra-day and inter-day precision of flucloxacillin were both less than 8.23%; The extraction recovery was in the range of 85.3%-89.2%, and the matrix effect was between 89.3%-92.3%; The stability of plasma samples was good under conditions of 12 h at room temperature, 4 h at room temperature after treatment, repeated freeze-thaw for 3 times, and -20 ℃ freezing for 30 d. The results of clinical samples indicated that the combination of ambroxol could significantly increase the blood concentration of flucloxacillin. CONCLUSION The established HPLC-MS/MS method is accurate, sensitive and can be used for the determination of flucloxacillin concentration in neonatal plasma. The results of clinical samples indicate that ambroxol can significantly increase the blood concentration of flucloxacillin. There are drug interactions between ambroxol and flucloxacillin.