Применение методов атомно-силовой микроскопии и органотипической культуры ткани для исследования действия на мембрану сенсорного нейрона аргининсодержащего короткого пептида, претендующего на роль анальгетической лекарственной субстанции

Abstract

Opiate use to treat chronic pain is known to be associated with negative side effects. Therefore, the development of new safe and effective non-opioid analgesics is both important and urgent goal of modern science. Previously, we showed that tetrapeptide Ac-RERR-NH2 has potential as an analgesic drug substance, since it can reduce the excitability of nociceptive neurons responsible for encoding nociceptive signals. The effect of sub-nanomolar concentration of Ac-RERR-NH2 tetrapeptide on embryonic sensory neurons was investigated with the use of atomic force microscopy (AFM) and organotypic tissue culture method. The quasi-static PeakForce QNM AFM mode was used, which allows mapping of local mechanical cell properties. Following administration of the substance, sensory neurons tended to decrease their stiffness. This result is based on the analysis of the values of the apparent Young’s modulus of sensory neurons and their deformation, controlled for the slipping of the tip of the probe over the surface under study. The area index (AI) criterion showed that the studied tetrapeptide has pronounced neurite-stimulating properties. The data obtained suggest that Ac-RERR-NH2, acting at very low concentrations, is able to trigger an as yet unidentified intracellular cascade regulating the growth of neurites of sensory neurons.