Synergistic effect of CNTF and GDNF on directed neurite growth in chick embryo dorsal root ganglia

• Published in: PloS one 2020-10, Vol.15 (10), p.e0240235
• Main Authors: Mashanov, Vladimir, Alwan, Abdelrahman, Kim, Michael W, Lai, Dehui, Poerio, Aurelia, Ju, Young Min, Kim, Ji Hyun, Yoo, James J
• Format: Article
• Language: English
• Subjects: Animals; Axonogenesis; Bioengineering; Biology and Life Sciences; Cell culture; Cells, Cultured; Chick Embryo; Ciliary neurotrophic factor; Ciliary Neurotrophic Factor - pharmacology; Collagen; Dorsal root ganglia; Elongation; Embryonic development; Embryos; Ganglia; Ganglia, Spinal - drug effects; Ganglia, Spinal - embryology; Ganglia, Spinal - metabolism; Glial cell line-derived neurotrophic factor; Glial Cell Line-Derived Neurotrophic Factor - pharmacology; Hydrogels; In vitro methods and tests; Medical research; Medicine; Medicine and Health Sciences; Nervous system; Neurites - drug effects; Neurites - metabolism; Neurogenesis - drug effects; Neuronal-glial interactions; Neurons - drug effects; Neurons - metabolism; Neurotrophic factors; Observations; Peripheral nerves; Physical Sciences; Physiological aspects; Research and Analysis Methods; Signal Transduction - drug effects; Synergistic effect; Tissue culture
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0240235

It is often critical to improve the limited regenerative capacity of the peripheral nerves and direct neural growth towards specific targets, such as surgically implanted bioengineered constructs. One approach to accomplish this goal is to use extrinsic neurotrophic factors. The candidate factors first need to be identified and characterized in in vitro tests for their ability to direct the neurite growth. Here, we present a simple guidance assay that allows to assess the chemotactic effect of signaling molecules on the growth of neuronal processes from dorsal root ganglia (DRG) using only standard tissue culture materials. We used this technique to quantitatively determine the combined and individual effects of the ciliary neurotrophic factor (CNTF) and glial cell line-derived neurotrophic factor (GDNF) on neurite outgrowth. We demonstrated that these two neurotrophic factors, when applied in a 1:1 combination, but not individually, induced directed growth of neuronal processes towards the source of the gradient. This chemotactic effect persists without significant changes over a wide (10-fold) concentration range. Moreover, we demonstrated that other, more general growth parameters that do not evaluate growth in a specific direction (such as, neurite length and trajectory) were differentially affected by the concentration of the CNTF/GNDF mixture. Furthermore, GDNF, when applied individually, did not have any chemotactic effect, but caused significant neurite elongation and an increase in the number of neurites per ganglion.