title: Enhanced neurite outgrowth of human model (NT2) neurons by small-molecule inhibitors of Rho/ROCK signaling.
abstract: Axonal injury in the adult human central nervous system often results in loss of sensation and motor functions. Promoting regeneration of severed axons requires the inactivation of growth inhibitory influences from the tissue environment and stimulation of the neuron intrinsic growth potential. Especially glial cell derived factors, such as chondroitin sulfate proteoglycans, Nogo-A, myelin-associated glycoprotein, and myelin in general, prevent axon regeneration. Most of the glial growth inhibiting factors converge onto the Rho/ROCK signaling pathway in neurons. Although conditions in the injured nervous system are clearly different from those during neurite outgrowth in vitro, here we use a chemical approach to manipulate Rho/ROCK signalling with small-molecule agents to encourage neurite outgrowth in cell culture. The development of therapeutic treatments requires drug testing not only on neurons of experimental animals, but also on human neurons. Using human NT2 model neurons, we demonstrate that the pain reliever Ibuprofen decreases RhoA (Ras homolog gene family, member A GTPase) activation and promotes neurite growth. Inhibition of the downstream effector Rho kinase by the drug Y-27632 results in a strong increase in neurite outgrowth. Conversely, activation of the Rho pathway by lysophosphatidic acid results in growth cone collapse and eventually to neurite retraction. Finally, we show that blocking of Rho kinase, but not RhoA results in an increase in neurons bearing neurites. Due to its anti-inflammatory and neurite growth promoting action, the use of a pharmacological treatment of damaged neural tissue with Ibuprofen should be explored.
authors.affiliation: Division of Cell Biology, University of Veterinary Medicine Hannover, Bischofsholer Damm 15/102, 30173, Hannover, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Roloff
authors.affiliation: Division of Cell Biology, University of Veterinary Medicine Hannover, Bischofsholer Damm 15/102, 30173, Hannover, Germany.
authors.forename: Hannah
authors.initials: H
authors.lastname: Scheiblich
authors.affiliation: Division of Cell Biology, University of Veterinary Medicine Hannover, Bischofsholer Damm 15/102, 30173, Hannover, Germany.
authors.forename: Carola
authors.initials: C
authors.lastname: Dewitz
authors.affiliation: Division of Cell Biology, University of Veterinary Medicine Hannover, Bischofsholer Damm 15/102, 30173, Hannover, Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: Dempewolf
authors.affiliation: Division of Cell Biology, University of Veterinary Medicine Hannover, Bischofsholer Damm 15/102, 30173, Hannover, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Stern
authors.affiliation: Division of Cell Biology, University of Veterinary Medicine Hannover, Bischofsholer Damm 15/102, 30173, Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Bicker
mesh_terms: D002460:Cell Line; D002470:Cell Survival; D004789:Enzyme Activation; D006801:Humans; D016501:Neurites / Q000187:drug effects* / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects*; D054460:rho-Associated Kinases / Q000378:metabolism*
chemical_list: D047428:Protein Kinase Inhibitors; D054460:rho-Associated Kinases