Neurotrophin signaling is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Neurotrophins are a family of growth factors that play crucial roles in the development, survival, and function of [neurons](/cell-types/neurons) throughout the lifespan[@huang2001]. They include nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4 (NT-4)[@barde1994]. Dysregulation of neurotrophin signaling has been strongly implicated in the pathogenesis of Alzheimer's disease, Parkinson's disease, and other neurodegenerative disorders[@allen2011].
Overview
Neurotrophins exert their effects by binding to two classes of receptors[@chao1992]:
p75^NTR: A low-affinity pan-neurotrophin receptor that can signal independently or cooperate with Trk receptors
Trk receptors: Tyrosine kinase receptors (TrkA, TrkB, TrkC) with high specificity for different neurotrophins
The balance between pro-neurotrophins and mature neurotrophins, along with receptor expression patterns, determines the ultimate biological outcome.
Neurotrophin Family
Nerve Growth Factor (NGF)
NGF was the first discovered neurotrophic factor and is essential for[@levi1987]:
...
Neurotrophin Signaling in Neurodegeneration
Introduction
Neurotrophin signaling is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Neurotrophins are a family of growth factors that play crucial roles in the development, survival, and function of [neurons](/cell-types/neurons) throughout the lifespan[@huang2001]. They include nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4 (NT-4)[@barde1994]. Dysregulation of neurotrophin signaling has been strongly implicated in the pathogenesis of Alzheimer's disease, Parkinson's disease, and other neurodegenerative disorders[@allen2011].
Overview
Neurotrophins exert their effects by binding to two classes of receptors[@chao1992]:
p75^NTR: A low-affinity pan-neurotrophin receptor that can signal independently or cooperate with Trk receptors
Trk receptors: Tyrosine kinase receptors (TrkA, TrkB, TrkC) with high specificity for different neurotrophins
The balance between pro-neurotrophins and mature neurotrophins, along with receptor expression patterns, determines the ultimate biological outcome.
Neurotrophin Family
Nerve Growth Factor (NGF)
NGF was the first discovered neurotrophic factor and is essential for[@levi1987]:
Development and maintenance of sympathetic neurons
Survival of sensory neurons, particularly nociceptive and thermoceptive neurons
Cholinergic neuron survival in the basal forebrain
Pain perception and thermal regulation
Brain-Derived Neurotrophic Factor (BDNF)
BDNF is the most widely expressed neurotrophin in the brain and is critical for[@lu2008]:
Synaptic plasticity and memory formation
Hippocampal neuron survival
Cognitive function
Mood regulation
Neurotrophin-3 (NT-3)
NT-3 supports[@ernfors1990]:
Development of multiple neuronal populations
Proprioceptive sensory neurons
Cerebellar development
Axon guidance during development
Neurotrophin-4 (NT-4)
NT-4 is important for[@ip1993]:
Peripheral neuron survival
hippocampal synaptic plasticity
Wound healing
Signaling Mechanisms
Trk Receptor Signaling
Upon neurotrophin binding, Trk receptors dimerize and autophosphorylate, activating multiple downstream pathways[@apapatoutian2001]:
PI3K/Akt Pathway: Promotes cell survival through phosphorylation of BAD
Ras/ERK Pathway: Regulates neuronal differentiation and synaptic plasticity
PLC-γ Pathway: Modulates calcium signaling and gene transcription
p75^NTR Signaling
The p75^NTR receptor can activate diverse signaling pathways[@roux2002]: