International Journal of Nanomedicine (Sep 2019)
Biological Activity Of miRNA-27a Using Peptide-based Drug Delivery Systems
Abstract
Anna-Laurence Schachner-Nedherer,1 Oliver Werzer,1 Karin Kornmueller,2 Ruth Prassl,2 Andreas Zimmer1 1Department of Pharmaceutical Technology and Biopharmacy, Institute of Pharmaceutical Sciences, University of Graz, Graz 8010, Austria; 2Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Biophysics, Medical University of Graz, Graz 8010, AustriaCorrespondence: Andreas ZimmerInstitute of Pharmaceutical Sciences, Department of Pharmaceutical Technology and Biopharmacy, University of Graz, Graz 8010, AustriaEmail [email protected]: Endogenously expressed microRNAs (miRNAs) have attracted attention as important regulators in post-transcriptionally controlling gene expression of various physiological processes. As miRNA dysregulation is often associated with various disease patterns, such as obesity, miRNA-27a might therefore be a promising candidate for miRNA mimic replacement therapy by inhibiting adipogenic marker genes. However, application of naked nucleic acids faces some limitations concerning poor enzymatic stability, bio-membrane permeation and cellular uptake. To overcome these obstacles, the development of appropriate drug delivery systems (DDS) for miRNAs is of paramount importance.Methods: In this work, a triple combination of atomic force microscopy (AFM), brightfield (BF) and fluorescence microscopy was used to trace the cellular adhesion of N-TER peptide-nucleic acid complexes followed by time-dependent uptake studies using confocal laser scanning microscopy (cLSM). To reveal the biological effect of miRNA-27a on adipocyte development after transfection treatment, Oil-Red-O (ORO)- staining was performed to estimate the degree of in lipid droplets accumulated ORO in mature adipocytes by using light microscopy images as well as absorbance measurements.Results: The present findings demonstrated that amphipathic N-TER peptides represent a suitable DDS for miRNAs by promoting non-covalent complexation through electrostatic interactions between both components as well as cellular adhesion of the N-TER peptide – nucleic acid complexes followed by uptake across cell membranes and intracellular release of miRNAs. The anti-adipogenic effect of miRNA-27a in 3T3-L1 cells could be detected in mature adipocytes by reduced lipid droplet formation.Conclusion: The present DDS assembled from amphipathic N-TER peptides and miRNAs is capable of inducing the anti-adipogenic effect of miRNA-27a by reducing lipid droplet accumulation in mature adipocytes. With respect to miRNA mimic replacement therapies, this approach might provide new therapeutic strategies to prevent or treat obesity and obesity-related disorders.Keywords: drug delivery system, DDS, miRNA-27a, amphipathic peptides, anti-adipogenic effect, 3T3-L1 cells
