Int J Med Sci
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The promoter is a major element in the expression cassette of gene therapy vectors. Optimal promoter selection can enhance target specificity and gene expression. Recently, we evaluated three different human elongation factor 1 alpha (EF1α) promoters. ⋯ The activity from one EF1α promoter (termed EF1α -3), obtained in a commercial vector, was markedly lower when tested in vitro (from 50 - 500 x) in four cell lines and in vivo in rat submandibular glands (~250 x). Sequence differences in the EF1α -3 promoter likely account for the activity differences seen. Investigators need to recognize that all promoters of the same name may not be equivalent in driving transgene expression.
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Although the protective effects of levocarnitine in patients with ischemic heart disease are related to the attenuation of oxidative stress injury, the exact mechanisms involved have yet to be fully understood. Our aim was to investigate the potential protective effects of levocarnitine pretreatment against oxidative stress in rat H9c2 cardiomyocytes. ⋯ Our in vitro study indicated that levocarnitine pretreatment may protect cardiomyocytes from oxidative stress-related damage.
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To determine whether microwave (MW) radiation induces neural cell apoptosis, differentiated PC12 cells and Wistar rats were exposed to 2.856 GHz for 5 min and 15 min, respectively, at an average power density of 30 mW/cm². JC-1 and TUNEL staining detected significant apoptotic events, such as the loss of mitochondria membrane potential and DNA fragmentation, respectively. Transmission electron microscopy and Hoechst staining were used to observe chromatin ultrastructure and apoptotic body formation. ⋯ Furthermore, the ratio of Bax/Bcl-2, expression of cytochrome c, cleaved caspase-3 and PARP all increased. In conclusion, microwave radiation induced neural cell apoptosis via the classical mitochondria-dependent caspase-3 pathway. This study may provide the experimental basis for further investigation of the mechanism of the neurological effects induced by microwave radiation.
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Apolipoprotein M (APOM) has been suggested as a vasculoprotective constituent of high density lipoprotein (HDL), which plays a crucial role behind the mechanism of HDL-mediated anti-atherosclerosis. Previous studies demonstrated that insulin resistance could associate with decreased APOM expressions. In agreement with our previous reports, here, we further confirmed that the insulin sensitivity was also reduced in rats treated with high concentrations of glucose; such effect could be reversed by administration of rosiglitazone, a peroxisome proliferator-activated receptor-γ (PPARγ). ⋯ Two-way ANOVA analysis demonstrated that the interactions between rosiglitazone and infusion of 25% glucose solution on Shp1 (P=0.0054) and Abca1 (4E, P=0.0004) mRNA expression was statistically significant. It is concluded that rosiglitazone could increase Apom expression, of which the detailed mechanism needs to be further investigated. The downregulation of Apom by hyperglycemia might be mainly through decreasing expression of Pparg and followed by inhibiting Lxrb in rats.
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Vector delivery is still a bottleneck for gene therapy. To overcome some disadvantages of adenoviral and retroviral vectors, we developed a hybrid vector. This hybrid vector, AdLTR-luc, was created by adding two elements from Moloney murine leukemia virus (MoMLV) flanking the luciferase cDNA into an E1/E3-deleted, replication deficient serotype 5 adenovirus vector (Zheng et al., Nature Biotechnol, 2000), and demonstrated that the MoMLV element upstream of the luciferase cDNA was broken during the integration event. ⋯ Digestion of genomic DNA with either Xba I/Kpn I, Bam HI/Sac I, or Bam HI/Nco I demonstrated that the MoMLV downstream element was also broken during integration. A PCR assay was unable to amplify the junctional region between the downstream MoMLV element and the adenoviral E2B gene, consistent with a break in that element. Although AdLTR-luc integration is atypical (Zheng et al., Nature Biotechnol, 2000), the present results suggest that both MoMLV elements have important roles in this event.