Kumar, P, Wu, H, McBride, JL, Jung, KE, Kim, MH, Davidson, BL et al.. Transvascular delivery of small interfering RNA to the central nervous system. Nature 448: 39-43

The CBR Institute for Biomedical Research and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA.
Nature (Impact Factor: 41.46). 08/2007; 448(7149):39-43. DOI: 10.1038/nature05901
Source: PubMed


A major impediment in the treatment of neurological diseases is the presence of the blood-brain barrier, which precludes the entry of therapeutic molecules from blood to brain. Here we show that a short peptide derived from rabies virus glycoprotein (RVG) enables the transvascular delivery of small interfering RNA (siRNA) to the brain. This 29-amino-acid peptide specifically binds to the acetylcholine receptor expressed by neuronal cells. To enable siRNA binding, a chimaeric peptide was synthesized by adding nonamer arginine residues at the carboxy terminus of RVG. This RVG-9R peptide was able to bind and transduce siRNA to neuronal cells in vitro, resulting in efficient gene silencing. After intravenous injection into mice, RVG-9R delivered siRNA to the neuronal cells, resulting in specific gene silencing within the brain. Furthermore, intravenous treatment with RVG-9R-bound antiviral siRNA afforded robust protection against fatal viral encephalitis in mice. Repeated administration of RVG-9R-bound siRNA did not induce inflammatory cytokines or anti-peptide antibodies. Thus, RVG-9R provides a safe and noninvasive approach for the delivery of siRNA and potentially other therapeutic molecules across the blood-brain barrier.

  • Source
    • "Mammalian expression plasmids encoding (1) wild-type Rab5, Rab7, Rab5(S34N), and Rab7(T22N) fused in frame to eGFP; and (2) a4, b2, and a6 (the latter fused to mCherry) subunits of the mammalian nAchR were transfected into Neuro2a cells using Lipofectamine 2000 48 hr prior to treatment with RVG-9R:siRNA complexes. Gene silencing was analyzed by flow cytometry for reporter GFP expression or qPCR for murine SOD1 and human CD4 mRNA levels (Kumar et al., 2007, 2008) normalizing to murine GAPDH and human beta-actin, respectively. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Cell-penetrating peptides (CPPs), such as nona-arginine (9R), poorly translocate siRNA into cells. Our studies demonstrate that attaching 9R to ligands that bind cell surface receptors quantitatively increases siRNA uptake and importantly, allows functional delivery of complexed siRNA. The mechanism involved accumulation of ligand-9R:siRNA microparticles on the cell membrane, which induced transient membrane inversion at the site of ligand-9R binding and rapid siRNA translocation into the cytoplasm. siRNA release also occurred late after endocytosis when the ligand was attached to the L isoform of 9R, but not the protease-resistant 9DR, prolonging mRNA knockdown. This critically depended on endosomal proteolytic activity, implying that partial CPP degradation is required for endosome-to-cytosol translocation. The data demonstrate that ligand attachment renders simple polycationic CPPs effective for siRNA delivery by restoring their intrinsic property of translocation. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Full-text · Article · Dec 2014 · Chemistry & Biology
  • Source
    • "In one example, beta-cyclodextrins were recently reported to deliver siRNA into the brain in vivo, knocking down Huntingtin (HTT) and alleviating motor deficits in a mouse model of HD (Godinho et al., 2013). Polyethylenimine (PEI) is another accepted delivery carrier for oligonucleotides that was shown to effectively deliver siRNAs to neurons, in vivo, on its own (Tan et al., 2005; Zintchenko et al., 2008), or to direct miRNA delivery into the brain, when conjugated to a glycoprotein, which provided affinity to acetylcholine receptors (Hwang do et al., 2011; Kumar et al., 2007). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Molecular genetics insight into the pathogenesis of several neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease and amyotrophic lateral sclerosis, encourage direct interference with the activity of neurotoxic genes or the molecular activation of neuroprotective pathways. Oligonucleotide-based therapies are recently emerging as an efficient strategy for drug development and these can be employed as new treatments of neurodegenerative states. Here we review advances in this field in recent years which suggest an encouraging assessment that oligonucleotide technologies for targeting of RNAs will enable the development of new therapies and will contribute to preservation of brain integrity.
    Full-text · Article · Apr 2014 · Brain research
  • Source
    • "Since its discovery in Caenorhabditis elegans [1], the RNA interference (RNAi) technique is emerging as a promising therapeutic modality for silencing disease-causing genes. Small interfering RNAs (siRNAs) containing ~ 21–23 nucleotides long double-stranded structures are finding increasing applications due to their easy design strategies and their high specificities for the target genes to be silenced [2] [3] [4] [5] [6] [7] [8] [9]. However , factors such as, susceptibility to serum nucleases, poor cellular uptake by the target organs/tissues, sub-optimal bioavailability, etc. are impeding clinical success of RNAi therapeutics. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Many cancer cells over express CDC20 (Cell Division Cycle homologue 20), a key cell cycle regulator required for the completion of mitosis in organisms from yeast to human. A recent in vitro study showed that specific knockdown of CDC20 expression using CDC20siRNA can significantly inhibit growth of human pancreatic carcinoma cells. However, preclinical study aimed at demonstrating therapeutic potential of CDC20siRNA in inhibiting tumor growth has just begun. Using a syngeneic C57BL/6J mouse tumor model, herein we show that intravenous administration of a 19bp synthetic CDC20siRNA encapsulated within α5β1 integrin receptor selective liposomes of pegylated RGDK-lipopeptide inhibits melanoma tumor growth. Liposomally encapsulated CDC20siRNA was found to be efficient in silencing the expression of CDC20 in tumor and endothelial cells at both mRNA and protein levels under in vitro settings. Findings in the flow cytometric studies confirmed the presence of significantly enhanced populations of the G2/M phase in cells treated with liposomally encapsulated CDC20siRNA. Immunohistochemical staining of tumor cryosections from mice treated with liposomally encapsulated fluorescently labeled siRNAs revealed tumor vasculatures targeting capabilities of the present liposomal formulations. The colocalizations of the TUNEL and VE-cadherin positive cells in tumor cryosections are consistent with tumor growth inhibition being mediated via apoptosis of the tumor endothelial cells. In summary, the presently disclosed liposomal formulation of CDC20siRNA is a promising RNA interference tool for use in anti-angiogenic cancer therapy.
    Full-text · Article · Apr 2014 · Journal of Controlled Release
Show more