PNAs: Taxi transports protein into spinal cord

February 18, 2016 / BIOON / -- a small peptide called "taxis" has lived up to its name Recent studies have shown that after intramuscular injection, it can be used as an effective vehicle to transport functional proteins (such as active enzymes) into the spinal cord The findings suggest that taxi is expected to deliver biopharmaceuticals to the inaccessible spinal cord Peptides are short chain amino acid building blocks that are useful for specific biological activities Taxi represents the role of this special peptide, targeted axonal import Through an unusual delivery path, taxi does not have to face the natural barrier between blood and the spine and brain This barrier can protect against harmful substances, but it can also block useful drugs In a recent study published in proceedings of the National Academy of Sciences, researchers at the University of Washington showed that mice injected with taxis intramuscularly could transport recombinant proteins to spinal motor neurons Spinal motor neurons are located in the spinal cord, but they expand their fibers to connect and control muscle movement "Biotherapy, such as protein or nucleic acid, is known to be difficult to access the central nervous system," said Suzie Hwang pun, senior author of the study and professor of bioengineering at the University of Washington "Our team initiated this work to develop delivery vehicles that can enter the spinal cord by mimicking the pathways of some viruses and toxins "Other laboratories have been trying to design delivery systems for denatured human viruses, such as herpes simplex, to tap into the habits of these viruses entering nerve cells in the brain and spinal cord The taxi peptide approach avoids problems associated with the use of these viruses, such as safety concerns, high production costs, dosage control issues, and immune responses "We believe that taxi could be a significant advance in the development of therapies for motor neuron disease," pun said An example of motor neuron disease is lugaremia, or amyotrophic lateral sclerosis (ALS) In patients with ALS, muscle atrophy progresses until breathing and swallowing are affected Drew sellers, lead author of the study and assistant professor of bioengineering at the University of Washington, discovered the transport capacity of taxi by screening a large peptide sequence library from transgenic phages Researchers are trying to overcome a major obstacle in the treatment of neurodegenerative diseases: the lack of effective, minimally invasive technology to deliver macromolecular drugs into the brain and spinal cord Sellers was interested in repairing spinal cord injury in the course of regenerative medicine research with Philip Horner Horner is a co senior author of the study, previously at the University of Washington and now director of neurodegenerative medicine at the Houston Methodist Institute Taxi can enter the axon through the intramuscular injection site and bypass the blood / spinal cord barrier The injection site of mice was similar to that of human calf muscles Taxi was then selectively accumulated in the lumbar spinal cord Taxi was introduced into human spinal cord samples in the laboratory, and the peptide was labeled to motoneurons Sellers said he didn't expect taxi to work so well Now we have completed the early concept verification experiment The next step is to clarify its mechanism and apply it to the model of motor neuron disease If it continues to succeed in these additional tests, clinical applications will be developed This study of taxi opens the door to a variety of neurodegenerative diseases, a technique that is milder for patients than catheterization into the spinal cord or other painful surgical procedures "It's now possible to design taxi to deliver drugs directly to specific areas of the spinal cord and brain," sellers said (Bio Valley bio Com) this article is the original compilation and collation of Bio Valley, welcome to reprint! Click for authorization For more information, please download Biovalley app