Article

A means for targeting therapeutics to peripheral nervous system neurons with axonal damage

Neurosurgery (Impact Factor: 3.62). 06/2007; 60(5):911-8; discussion 911-8. DOI: 10.1227/01.NEU.0000255444.44365.B9
Source: PubMed

ABSTRACT

Delivery of biological therapeutics to motor and dorsal root ganglion neurons remains a major hurdle in the development of treatments for a variety of neurological processes, including peripheral nerve injury, pain, and motor neuron diseases. Because nerve cell bodies are important in initiating and controlling axonal regeneration, targeted delivery is an appealing strategy to deliver therapeutic proteins after peripheral nerve injury.
Tet1 is a 12-aa peptide, isolated through phage display that is selected for tetanus toxin C fragment-like binding properties. In this study, we surveyed its uptake and retrograde transport using compartmented cultures and sciatic nerve injections. We then characterized the time course of this delivery. Finally, to confirm the retrograde transport involvement, a colchicine pretreatment was performed. We also performed competitive binding studies between Tet1 and a recombinant tetanus toxin C fragment using recombinant tetanus toxin C fragment enzyme-linked immunosorbent assay.
We were able to demonstrate efficient uptake and retrograde axonal transport of the Tet1 peptide in vitro and in vivo. Intraneural colchicine pretreatment partially blocked fluorescence detection in the spinal cord, revealing a retrograde axonal transport mechanism. Finally, a competitive enzyme-linked immunosorbent assay experiment revealed Tet1-specific binding to the recombinant tetanus toxin C fragment axon terminal trisialogangliosides receptor.
These properties of Tet1 can be applied to the development of therapeutic viral vectors and fusion proteins for neuronal targeting and enhanced spinal cord delivery in the treatment of nerve regeneration, neuroprotection, analgesia, and spasticity. Small peptides can be easily fused to larger proteins without significantly modifying their function and can be used to alter the binding and uptake properties of these proteins.

0 Followers
 · 
19 Reads
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This chapter describes strategies for the analysis of gene expression and illustrates the power of such approaches in dissecting out the changing patterns of gene expression. It refers to both in vitro and in vivo methods for analyzing virulence gene expression. The term “in vitro” apply to any approach to study gene expression, in which the micro-organism is grown in vitro. The term “in vivo” is used to define the analysis of gene expression during growth of the micro-organism in the host animal or target tissue. The in vitro analysis of expression of a cloned gene can be regarded as the first step in understanding the expression of any putative virulence gene. It provides fundamental information, such as the location of the promoter, the level of gene expression, the pattern of expression in response to environmental changes in vitro, whether the gene is regulated at the level of transcription, translation, or post-translation, and the role of regulatory proteins in mediating expression of the gene. The chapter further discusses analysis of virulence gene expression in vitro.
    Preview · Article · Dec 1998
  • [Show abstract] [Hide abstract]
    ABSTRACT: Peripheral nerve diseases, also known as peripheral neuropathies, affect 15-20 million of Americans and diabetic neuropathy is the most common condition. Currently, the treatment of peripheral neuropathies is more focused on managing pain rather than providing permissive conditions for regeneration. Despite advances in microsurgical techniques, including nerve grafting and reanastomosis, axonal regeneration after peripheral nerve injury remains suboptimal. Also, no satisfactory treatments are available at this time for peripheral neurodegeneration occurring in motor neuron diseases (MND), including amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). Peripheral nerves have the inherent capacity of regeneration. Gene therapy strategies focused on neuroprotection may help optimizing axonal regrowth. A better understanding of the cellular and molecular events involved in axonal degeneration and regeneration have helped researchers to identify targets for intervention. This review summarizes the current state on the clinical experience as well as gene therapy strategies for peripheral neuropathies, including MND, peripheral nerve injury, neuropathic pain, and diabetic neuropathy.
    No preview · Article · Sep 2007 · Current Gene Therapy
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Neuron-targeted nucleic acid delivery systems are important technologies for realizing the potential of gene therapy for nervous system disorders. However, neurons are difficult cells to transfect using non-viral vectors due in part to the specific and unique delivery challenges present in these cells. We have investigated several bioactive peptides for their ability to assist in overcoming delivery barriers in mammalian cells. We summarize here our recent progress in developing and applying peptide-modified polycations for nucleic acid delivery. In addition, we present data demonstrating the potential of using multicomponent, peptide-modified polycations for nucleic acid delivery to neurons.
    Full-text · Article · Dec 2008 · Journal of Controlled Release
Show more