Liposome‐mediated messenger RNA: An alternative for fish cell transfection in culture

Abstract

Liposome-mediated plasmid DNA (pDNA) transfection is a relatively efficient transfection method that depends highly on actively dividing cells. However, numerous fish cells are mitotically inactive under in vitro culture conditions, thus limiting the application of liposome-mediated pDNA transfection. Liposome-mediated mRNA transfection is an attractive alternative in post-mitotic cells because it eliminates the transfer of genes into the nucleus and therefore is independent of cell proliferation. In this study, pDNA is compared with mRNA encoding biomarker proteins (enhanced green fluorescent protein [eGFP] and luciferase) mediated by cationic liposome in zebrafish embryo fibroblast cell line (ZF4), with or without proliferation restriction, and in mitotically inactive turbot liver primary cells. The results indicated that mRNA encoding eGFP exerted much higher transfection efficiency than pDNA in ZF4 cells. Moreover, mRNA encoding eGFP was detected and disappeared sooner than pDNA. Chemiluminescence of the biomarker protein luciferase showed that liposome-mediated mRNA transfection translated about threefold more protein without proliferation restriction and about tenfold more protein with proliferation restriction than pDNA transfection. In turbot liver cells, mRNA induced higher transfection efficiency and greater luciferase protein expression than pDNA. Greater PPARα expression and expression of downstream target genes were induced by mRNA rather than by pDNA transfection. In conclusion, cationic liposome-mediated mRNA is an alternative for fish cell transfection due to higher transfection efficiency and protein expression levels and faster translation onset.