No abstract

We discovered an epoch-making gene transfer method utilizing discharge plasma. Although an electroporation method is commonly used in present gene transfer experiments, it cannot transfer genes into primary cells sufficiently. The atmospheric pressure discharge plasma employed in this study was originally used for surface treatment of non-biological materials. We hypothesized that it could provide a suitable effect on the surface of target cells and applied it to gene transfer into various types of cells. The plasma technology succeeded in the efficient transfer of green fluorescence protein (GFP) plasmid into post-mitotic neuronal cells obtained from cerebral cortices of rats, into which an electroporation with conventional equipment cannot transfer genes sufficiently, as the cells were attached. After the transfection of rat pheochromocytoma PC12 cells with the GFP gene by plasma treatment, the cells retained their function, that is, nerve growth factor-induced differentiation. Furthermore, gene transfer with the plasma technology was also applicable to other types of cell lines such as HeLa cells and Chinese hamster lung (CHL) cells as adherent cell lines, and Jurkat cells as a suspended cell line, and another type of primary cell, human umbilical vein endothelial cells (HUVEC). In conclusion, the plasma method is an epoch-making gene transfer technology which efficiently transfers genes into primary cells into which electroporation cannot transfer genes. Moreover, the method is able to universally transfer genes into various types of cells as the function of the cells was maintained.

FK614 is a structurally novel class of peroxisome proliferator-activated receptor gamma (PPARgamma) agonist, with the mechanism of its insulin-sensitizing action most likely due to activation of PPARgamma. In this study, properties of FK614 for PPARgamma binding, ability to induce conformational change, and coactivator recruitment were investigated. FK614, rosiglitazone, and pioglitazone competed specific binding of [3H]rosiglitazone to PPARgamma with Ki values of 11 nM, 47 nM, and 1.3 microM, respectively. Limited trypsin digestion of PPARgamma with FK614 or rosiglitazone produced distinct patterns of digested polypeptides, suggesting that FK614 directly binds to PPARgamma but induces specific alterations in receptor conformation. FK614 induced interaction of PPARgamma with nuclear receptor coactivator CBP but of lower magnitude than rosiglitazone and pioglitazone. The estimated Kd values of FK614-, rosiglitazone-, and pioglitazone-PPARgamma complex to CBP peptide were 1.8, 0.64, and 0.72 microM, respectively, indicating FK614-PPARgamma complex exhibits a lower affinity for CBP peptide compared to other agonist-PPARgamma complexes. When tested the effect of FK614 on CBP recruitment induced by 9(S)-hydroxyoctadecadienoic acid, an endogenous ligand, FK614 negatively modulated PPARgamma activation. The unique properties of FK614 may underlie the molecular basis of ligand-dependent transcriptional modulation mediated by PPARgamma.