Identification of amino acid residues of nerve growth factor important for neurite outgrowth in human dorsal root ganglion neurons

Abstract

Nerve growth factor (NGF) is an essential neurotrophic factor for the development and maintenance of the central and the peripheral nervous system. NGF deficiency in the basal forebrain precedes degeneration of basal forebrain cholinergic neurons in Alzheimer's disease, contributing to memory decline. NGF mediates neurotrophic support via its high‐affinity receptor, the tropomyosin‐related kinase A (TrkA) receptor, and mediates mitogenic and differentiation signals via the extracellular signal‐regulated protein kinases 1 and 2 (ERK1/2). However, the molecular mechanisms underlying the different NGF/TrkA/ERK signalling pathways are far from clear. In this study, we have investigated the role of human NGF and three NGF mutants, R100E, W99A and K95A/Q96A, their ability to activate TrkA or ERK1/2, and their ability to induce proliferation or differentiation in human foetal dorsal root ganglion (DRG) neurons or in PC12 cells. We show that the R100E mutant was significantly more potent than NGF itself to induce proliferation and differentiation, and significantly more potent in activation of ERK1/2 in DRG neurons. The W99A and K95A/Q96A mutants, on the other hand, were less effective than the wild‐type protein. An unexpected finding was the high efficacy of the K95A/Q96A mutant to activate TrkA and to induce differentiation of DRG neurons at elevated concentrations. These data demonstrate an NGF mutant with improved neurotrophic properties in primary human neuronal cells. The R100E mutant represents an interesting candidate for further drug development in Alzheimer's disease and other neurodegenerative disorders.

Identification of Novel Positive Allosteric Modulators of Neurotrophin Receptors for the Treatment of Cognitive Dysfunction

“…We have previously reported that the activation of TrkA beyond 100% is possible when using PathHunter ® assays. For instance, a double mutant of NGF, NGF-K95A/Q96A, could activate the TrkA receptor to a higher degree than NGF itself [55]. We could also demonstrate that ACD855 positively modulated TrkA activity when tested at three different concentrations (0.3, 1 and 3 µM), together with a wide range of NGF concentrations, as judged by Figure 2c, depicting the NGF dose-response curves in the absence or presence of increasing concentrations of ACD855.…”

“…The resulting homogenate was mixed with 4X sample buffer and denatured by heating the mixture at 95 • C for 2 min. Western blot was performed as described previously [55].…”

Nerve growth factor and post-infarction cardiac remodeling

“…Он играет решающую роль в активации иммунной и эндокринной систем, в болевом пути, заживлении ран, росте аксонов и ремиелинизации [15,16]. Дисбаланс NGF/proNGF связан с воспалением и нейродегенерацией [25]. Всё больше данных свидетельствуют о том, что в дополнение к своим нейротрофическим функциям proNGF и NGF участвуют в нескольких биологических процессах, включая иммунный ответ, воспалительный ответ, лёгочную гипертензию, заживление ран и метастазирование рака [45,46,49].…”

“…В доступной литературе имеется достаточное количество статей, посвящённых структуре и функциям NGF в нервной и сердечно-сосудистой системах [22][23][24][25][26][27][28][29], однако обзорных работ, раскрывающих его роль в постинфарктном ремоделировании сердца, немного [30][31][32][33][34][35]. Научные источники по заданной теме были получены из базы данных PubMed с ключевыми словами из темы исследования: neurotrophins, nerve growth factor, postinfarction, cardiac remodeling.…”

Role of NGF and its receptors in wound healing (Review)

“…NGF and proNGF are essential neurotrophic factors for the development and maintenance of the central and peripheral nervous systems ( 30 , 31 ). In addition, NGF and proNGF play critical roles in the degeneration and repair events of neurological disorders, with different underlying aetiologies ( 32-34 ).…”