Effects of L1 adhesion molecule agonistic mimetics on signal transduction in neuronal functions

• Published in: Biochemical and biophysical research communications 2023-01, Vol.642, p.27-34
• Main Authors: Nagaraj, Vini, Kim, Roy, Martianou, Talia, Kurian, Shyam, Nayak, Ashana, Patel, Mukti, Schachner, Melitta, Theis, Thomas
• Format: Article
• Language: English
• Subjects: Agonists; Animals; L1CAM; Male; Mimetics; Neural Cell Adhesion Molecule L1 - metabolism; Neurite outgrowth; Neurites - metabolism; Neurogenesis; Neuronal migration; Neurons - metabolism; Signal Transduction
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2022.12.031

The L1 cell adhesion molecule plays an essential role in neural development and repair. It is not only a ‘lock and key’ recognition molecule, but an important signal transducer that stimulates regenerative-beneficial cellular functions such as neurite outgrowth, neuronal cell migration, survival, myelination, and synapse formation. Triggering L1 functions after neurotrauma improves functional recovery. In addition, loss-of-function mutations in the L1 gene lead to the L1 syndrome, a rare, X-linked neurodevelopmental disorder with an incidence of approximately 1:30,000 in newborn males. To use L1 for beneficial functions, we screened small compound libraries for L1 agonistic mimetics that trigger L1 functions and improve conditions in animal models of neurotrauma and the L1 syndrome. To understand the mechanisms underlying these functions, it is important to gain a better understanding of L1-dependent cellular signaling that is triggered by the L1 agonistic mimetics. We tested the cell signaling features of L1 agonistic mimetics that contribute to neurite outgrowth and neuronal migration. Our findings indicates that L1 agonistic mimetics trigger the same cell signaling pathways underlying neurite outgrowth, but only the L1 mimetics tacrine, polydatin, trimebutine and honokiol trigger neuronal migration. In contrast, the mimetics crotamiton and duloxetine did not affect neuronal migration, thus limiting their use in increasing neuronal migration, leaving open the question of whether this is a desired or not desired feature in the adult. •Functions of small compounds agonistically mimicking the cell adhesion molecule L1.•None of the L1 agonistic mimetics are neurotoxic at the tested concentrations.•Similar signal transducing cascades are activated by L1 mimetics and L1 function-triggering antibody.•However, unlike the function-triggering antibody, three out of seven tested mimetics do not stimulate neuronal migration.