Neurofilaments: light, medium, and heavy (abbreviated as NF-L, NF-M, and NF-H, respectively),
which belong to Type IV intermediate filament family (IF), are neuron-specific cytoskeletal components. Neurofilaments
are axonal structural components and integral components of synapses, which are important for neuronal
electric signal transmissions along the axons and post-translational modification. Abnormal assembly of
neurofilaments is found in several human neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS),
infantile spinal muscular atrophy (SMA), and hereditary sensory-motor neuropathy (HSMN). In addition, those
pathological neurofilament accumulations are known in α-synuclein in Parkinson’s disease (PD), Aβ and tau in
Alzheimer’s disease (AD), polyglutamine in CAG trinucleotide repeat disorders, superoxide dismutase 1 (SOD1),
TAR DNA-binding protein 43 (TDP43), neuronal FUS proteins, optineurin (OPTN), ubiquilin 2 (UBQLN2), and
dipeptide repeat protein (DRP) in amyotrophic lateral sclerosis (ALS). When axon damage occurs in central
nervous disorders, neurofilament proteins are released and delivered into cerebrospinal fluid (CSF), which are
then circulated into blood. New quantitative analyses and assay techniques are well-developed for the detection of
neurofilament proteins, particularly NF-L and the phosphorylated NF-H (pNF-H) in CSF and serum. This review
discusses the potential of using peripheral blood NF quantities and evaluating the severity of damage in the nervous
system. Intermediate filaments could be promising biomarkers for evaluating disease progression in different
nervous system disorders.
Differences in F-Wave Characteristics between Spinobulbar Muscular Atrophy and Amyotrophic Lateral Sclerosis