Faria Rúben, Paul Milan, Biswas Swati, Vivès Eric, Boisguérin Prisca, Sousa Ângela, Costa Diana
CICS-UBI-Health Sciences Research Centre, Universidade da Beira Interior, Avenida Infante D. Henrique, 6200-506 Covilha, Portugal.
Nanomedicine Research Laboratory, Department of Pharmacy, Birla Institute of Technology and Science-Pilani, Hyderabad Campus, Jawahar Nagar, Medchal, Hyderabad 500078, India.
Pharmaceutics. 2022 Mar 31;14(4):757. doi: 10.3390/pharmaceutics14040757.
Together with the nucleus, the mitochondrion has its own genome. Mutations in mitochondrial DNA are responsible for a variety of disorders, including neurodegenerative diseases and cancer. Current therapeutic approaches are not effective. In this sense, mitochondrial gene therapy emerges as a valuable and promising therapeutic tool. To accomplish this goal, the design/development of a mitochondrial-specific gene delivery system is imperative. In this work, we explored the ability of novel polymer- and peptide-based systems for mitochondrial targeting, gene delivery, and protein expression, performing a comparison between them to reveal the most adequate system for mitochondrial gene therapy. Therefore, we synthesized a novel mitochondria-targeting polymer (polyethylenimine-dequalinium) to load and complex a mitochondrial-gene-based plasmid. The polymeric complexes exhibited physicochemical properties and cytotoxic profiles dependent on the nitrogen-to-phosphate-group ratio (N/P). A fluorescence confocal microscopy study revealed the mitochondrial targeting specificity of polymeric complexes. Moreover, transfection mediated by polymer and peptide delivery systems led to gene expression in mitochondria. Additionally, the mitochondrial protein was produced. A comparative study between polymeric and peptide/plasmid DNA complexes showed the great capacity of peptides to complex pDNA at lower N/P ratios, forming smaller particles bearing a positive charge, with repercussions on their capacity for cellular transfection, mitochondria targeting and, ultimately, gene delivery and protein expression. This report is a significant contribution to the implementation of mitochondrial gene therapy, instigating further research on the development of peptide-based delivery systems towards clinical translation.
线粒体与细胞核一样，拥有自己的基因组。线粒体DNA突变会引发多种疾病，包括神经退行性疾病和癌症。目前的治疗方法并不有效。从这个意义上说，线粒体基因治疗成为一种有价值且有前景的治疗工具。为实现这一目标，设计/开发线粒体特异性基因递送系统势在必行。在这项工作中，我们探索了新型基于聚合物和肽的系统用于线粒体靶向、基因递送和蛋白质表达的能力，并对它们进行比较以揭示最适合线粒体基因治疗的系统。因此，我们合成了一种新型的线粒体靶向聚合物（聚乙烯亚胺-去铁胺）来负载和复合基于线粒体基因的质粒。聚合物复合物表现出取决于氮磷基团比（N/P）的物理化学性质和细胞毒性特征。荧光共聚焦显微镜研究揭示了聚合物复合物的线粒体靶向特异性。此外，由聚合物和肽递送系统介导的转染导致线粒体中的基因表达。另外，产生了线粒体蛋白。聚合物与肽/质粒DNA复合物之间的比较研究表明，肽在较低N/P比下复合pDNA的能力很强，形成带正电荷的较小颗粒，这对它们的细胞转染能力、线粒体靶向以及最终的基因递送和蛋白质表达产生影响。本报告对线粒体基因治疗的实施做出了重要贡献，促使对基于肽的递送系统的开发进行进一步研究以推动临床转化。
