Long-term modifications of blood pressure in normotensive and spontane-ously hypertensive rats by gene delivery of rAAV-mediated cytochrome P450 arachidonic acid hydroxylase

Arachidonic acid cytochrome P-450 （CYP） hydroxylase 4A isoforms, including 4A1, 4A2, 4A3 and 4A8 in the rat kidney, catalyze arachidonic acid to produce 19/20-Hydroxyeicosatetraenoic acids （20-HETE）, a biologically active metabolite, which plays an important role in the regulation of blood pressure. However, controversial results have been reported regarding the exact role of 20-HETE on blood pressure. In the present study, we used recombinant adenoassociated viral vector （rAAV） to deliver CYP 4A1 cDNA and antisense 4A1 cDNA into Sprague-Dawley （SD） rats and spontaneously hypertensive rats （SHR）, respectively, to investigate the effects of long-term modifications of blood pressure and the potential for gene therapy of hyperténsion. The mean systolic pressure increased by 14.2±2.5 mm Hg in rAAV.4A 1-treated SD rats and decreased by 13.7±2.2 mm Hg in rAAV.anti4A l-treated SHR rats 5 weeks after the injection compared with controls and these changes in blood pressure were maintained until the experiments ended at 24 weeks. In 4A1 treated animals CYP4A was overexpressed in various tissues, but preferentially in the kidney at both mRNA and protein levels. In anti-4Al-treated SHR, CYP4A mRNA in various tissues was probed, especially in kidneys, but 4A l protein expression was almost completely inhibited. These results suggest that arachidonic acid CYP hydroxylases contribute not only to the maintenance of normal blood pressure but also to the development of hypertension. rAAV-mediated anti4A administration strategy has the potential to be used as targeted gene therapy in human hypertension by blocking expression of CYP 4A in kidneys.

Transient over-expression of human papillomavirus type 16 E6 protein down-regulate the secretion of TNF-αor IL-1β LPS-induced from macrophages

In order to provide the experimental basis for the further studies on the oncogenic mechanism of the E6 protein from human papillomavirus type 16 （HPV16）, the eukaryotic expression vector pcDNA3.1 （-）/E6 was used for the study on the effect of E6 protein to influence the secretory activity of LPS-induced 3MP-1-macrophages, and the reconstructed plasmid pcDNA3.1 （-）/E6 was transfected into THP-1-macrophages. The expression of E6 gene was assayed in macrophage lysates by using Western blot analysis and the level of TNF-α or IL-1β was examined by ELISA. All of data were analyzed by SPSS12.0. As demonstrated by Western blot analysis, the expression of E6 protein with a molecular weight of about 18 kDa by plasmid pcDNA3.1 （-）/E6 in THP-1-macrophages could be detected. However, as demonstrated by ELISA assay, the level of TNF-α or IL-1β in lysates of THP-1-macrophages showed an obvious difference between the pcDNA3.1 （-）/E6 group and the LPS control group or the pcDNA3.1 （-） control group （P 〈 0.01）, but no significant difference existed between pcDNA3.1 （-） control group and LPS control group （ P 〉 0.05）. All these results illustrate that the transient over-expression of HPV6 E6 protein reduces the production of TNF-α and IL-1β induced by LPS in THP-1-macrophages.