title: Intracellular trafficking and exocytosis of a multi-component siRNA nanocomplex.
abstract: Despite the importance of siRNA delivery systems, understanding of their intracellular fate remains elusive. We recently developed a multi-component siRNA nanocomplex to deliver siRNA to hepatic stellate cells (HSCs). The objective of this study is to study post-internalization trafficking of this siRNA nanocomplex and its multiple components like siRNA, protamine, and streptavidin, in HSCs. After internalization, the nanocomplex entrapped in early endosomes undergoes three possible routes including endosomal escape, exocytosis, and entrapment in lysosomes. Significant amount of siRNA dissociates from the nanocomplex to exert silencing activity. After escaping from endosomes, protamine dissociates from the nanocomplex and stays inside the cytoplasm. Golgi complex plays an important role in exocytosis of the nanocomplex. We also demonstrate that exocytosis is one of the major reasons accounting for the transient silencing activity of nonviral siRNA delivery. Incorporation of exocytosis inhibitors in nonviral siRNA delivery systems may extend the silencing activity of siRNA.
authors.affiliation: Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO, USA.
authors.forename: Ravi S
authors.initials: RS
authors.lastname: Shukla
authors.affiliation: Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO, USA.
authors.forename: Akshay
authors.initials: A
authors.lastname: Jain
authors.affiliation: Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO, USA.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO, USA. Electronic address: chengkun@umkc.edu.
authors.forename: Kun
authors.initials: K
authors.lastname: Cheng
mesh_terms: D011992:Endosomes; D005089:Exocytosis; D020868:Gene Silencing; D055166:Hepatic Stellate Cells; D006801:Humans; D007202:Indicators and Reagents / Q000493:pharmacokinetics*; D053758:Nanoparticles; D034741:RNA, Small Interfering; D019809:Streptavidin / Q000493:pharmacokinetics*
chemical_list: D007202:Indicators and Reagents; D034741:RNA, Small Interfering; D019809:Streptavidin
keywords: Exocytosis; Hepatic stellate cells; Intracellular trafficking; Nanocomplex; siRNA delivery