Synthesis and Exon-Skipping Properties of a 3'-Ursodeoxycholic Acid-Conjugated Oligonucleotide Targeting DMD Pre-mRNA: Pre-Synthetic versus Post-Synthetic Approach

Topical Application of Peptide Nucleic Acid Antisense Oligonucleotide for MMP-1 and Its Potential Anti-Aging Properties

Matrix metalloproteinase-1 (MMP-1) is a zinc-containing endopeptidase that degrades dermal collagen and other extracellular matrix molecules. It is recognized as one of the most important indicators of cellular senescence and age-related skin changes. Here, we introduced a novel MMP-1 peptide nucleic acid (PNA) derivative-PNA-20 carboxyethyl fluorene (CEF)-which can interact with and consequently silence the MMP-1 gene sequence. The investigation on the efficacy of PNA-20 CEF in MMP-1 silencing in human dermal fibroblasts revealed significantly decreased expression of MMP-1 at both gene and protein levels. Treatment with PNA-20 CEF showed significantly increased expression of collagen I protein, indicating its potential role in preventing the degradation of collagen I and consequently combating the skin aging process. Its topical application on 3D human skin tissue showed successful absorption into the epidermis and the upper dermis. Furthermore, the additional 4-week single-arm prospective study on 21 Asian women revealed improvements in facial wrinkles, skin moisture, elasticity, and density after the use of the topical PNA-20 CEF cosmeceutical formulation. Additional in-vitro and ex-vivo studies are needed for a comprehensive understanding of the skin anti-aging effects of MMP-1 PNA.

Antisense Oligonucleotides Conjugated with Lipophilic Compounds: Synthesis and In Vitro Evaluation of Exon Skipping in Duchenne Muscular Dystrophy

Our groups previously reported that conjugation at 3′-end with ursodeoxycholic acid (UDCA) significantly enhanced in vitro exon skipping properties of ASO 51 oligonucleotide targeting the human DMD exon 51. In this study, we designed a series of lipophilic conjugates of ASO 51, to explore the influence of the lipophilic moiety on exon skipping efficiency. To this end, three bile acids and two fatty acids have been derivatized and/or modified and conjugated to ASO 51 by automatized solid phase synthesis. We measured the melting temperature (T_m) of lipophilic conjugates to evaluate their ability to form a stable duplex with the target RNA. The exon skipping efficiency has been evaluated in myogenic cell lines first in presence of a transfection agent, then in gymnotic conditions on a selection of conjugated ASO 51. In the case of 5′-UDC-ASO 51, we also evaluated the influence of PS content on exon skipping efficiency; we found that it performed better exon skipping with full PS linkages. The more efficient compounds in terms of exon skipping were found to be 5′-UDC- and 5′,3′-bis-UDC-ASO 51.